DA0-002 · domain
software troubleshooting
Practise CompTIA Data+ (DA0-002) software troubleshooting practice questions — original exam-style scenarios with answer choices, explanations, and analysis of common mistakes.
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What to know about software troubleshooting
software troubleshooting questions test whether you can apply the concept in context, not just recognise a definition.
How the topic appears in realistic exam-style scenarios.
Which detail in the question changes the correct answer.
How to eliminate plausible but wrong options.
How to connect the question back to the wider exam objective.
Watch out for
Common software troubleshooting exam traps
- ▸Answering from memory before reading the full scenario.
- ▸Missing a constraint such as cost, availability, security, scope or command context.
- ▸Choosing a broad answer when the question asks for the most specific fix.
- ▸Ignoring why the wrong options are tempting.
Question index
All software troubleshooting questions (986)
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A business analyst creates a one-time report to analyze customer churn for a special project. Which report type is being used?
Easy2A healthcare provider needs to integrate patient data from multiple clinics into a single data warehouse. Which process is used to extract, transform, and load the data?
Easy3An analyst runs an A/B test with 1000 users per group and observes a conversion rate of 5% in the control and 6% in the treatment. The p-value is 0.12. What should the analyst conclude?
Hard4Refer to the exhibit. Before running the code, the original salary column had 50 missing values. The median was calculated as 52000. After imputation, which of the following statements is true?
Hard5An analyst is using Python pandas and has a DataFrame 'sales' with columns 'date', 'product', 'revenue'. They need to create a pivot table showing total revenue per product per month. Which pandas function is most appropriate?
Hard6In A/B testing, the null hypothesis typically states that:
Easy7A data analyst needs to identify the top 3 most frequent product categories from a sales table. Which SQL techniques can be used to achieve this? (Choose two.)
Hard8A data analyst wants to show the relative proportions of defects by type in a manufacturing process. There are 6 defect types. Which chart is most appropriate?
Easy9A retail company wants to analyze customer purchase patterns over time. The data is stored in a relational database with tables for Customers, Orders, and Products. Which database concept should be used to ensure that each order references a valid customer?
Medium10An analyst wants to show the trend of monthly sales over the past two years. Which chart type is most appropriate?
Easy11A healthcare organization is subject to strict data privacy regulations requiring the classification of all data assets. The data governance team has identified three data sensitivity levels: Public, Internal, and Restricted. They have a new data pipeline importing patient health records from multiple clinics. The records include patient names, diagnoses, treatment codes, and insurance information. The team must ensure that the classification is applied correctly and that restricted data (e.g., diagnoses) is not exposed to unauthorized personnel. However, the pipeline uses automated tagging based on metadata rules, and some fields are misclassified. What is the most effective immediate action to improve classification accuracy?
Hard12Which TWO of the following are benefits of database normalization to 3NF? (Select 2)
Medium13Which TWO of the following are effective techniques for presenting data to a non-technical audience?
Easy14A data analyst wants to visualize the number of website visitors by traffic source (e.g., organic, paid social, email) and also show the proportion of each source within the total. Which chart type is best?
Medium15An analyst computed the mean, median, and mode of a dataset and found they are all equal. Which of the following best describes the distribution?
Easy16An analyst needs to present quarterly sales data to the board. The CEO wants to see both overall trend and breakdown by region. Which dashboard layout is most effective?
Medium17A time series of monthly sales data exhibits a clear upward trend over several years, with consistent peaks each December. Which components are present in this series?
Hard18A dataset contains a feature with values ranging from 10 to 1000. The analyst applies min-max normalization to scale the feature between 0 and 1. What is the normalized value of 520?
Hard19A data analyst needs to count the number of orders placed by each customer, but only for customers who have placed more than 5 orders. Which SQL clause should be used to filter the aggregated results?
Medium20A government agency's data analyst is commissioned to produce a report on public transportation usage trends. The report will be read by policymakers, transit planners, and the general public. The data includes ridership numbers, delay rates, and demographic breakdowns. The analyst needs to ensure the report is accessible and persuasive, especially to non-technical readers. The goal is to advocate for increased funding in underserved areas. The report must be data-driven but also tell a compelling story. What strategy should the analyst prioritize?
Hard21A company uses a dashboard to monitor server uptime. The data is collected every minute, but the dashboard only refreshes every hour. Users see gaps in the line chart. What is the most likely cause, and how should it be fixed?
Hard22A data analyst is creating a dashboard for a retail company. The dashboard should provide insights into sales performance across multiple dimensions. Which TWO chart types are best suited for showing the contribution of each product category to total sales?
Medium23Which chart type is best for comparing the distribution of a continuous variable across different categories?
Easy24A data analyst wants to show the distribution of customer ages for a retail store. The ages are continuous and the analyst needs to visualize the frequency of different age ranges. Which chart type is most appropriate?
Easy25A data analyst discovers an anomaly in a dataset. Which two actions should be taken before reporting? (Choose TWO.)
Easy26A data analyst needs to combine customer data from two tables: Customers (CustomerID, Name) and Orders (OrderID, CustomerID, Amount). Only customers who have placed at least one order should be included. Which JOIN type should be used?
Hard27A large retail company is integrating customer data from two separate CRM systems into a new data warehouse. System A stores customer IDs as integers (e.g., 12345), while System B stores them as alphanumeric strings (e.g., 'CUST-12345-X'). Additionally, some customers exist in both systems but with slight name variations (e.g., 'John Smith' vs 'Jon Smith'). The data warehouse requires a unified customer table with a single unique identifier for each customer. The analyst needs to design the data acquisition process. Which of the following is the most appropriate first step?
Hard28A data analyst needs to show the cumulative revenue over time, with emphasis on the total magnitude. Which chart type is most appropriate?
Medium29An analyst is comparing the average sales of two different store locations using a t-test. The p-value obtained is 0.03, and the significance level is 0.05. What should the analyst conclude?
Medium30A data analyst is working with a dataset that includes customer names, email addresses, and purchase history. The analyst wants to ensure that each customer is uniquely identified. Which TWO database concepts should be used to enforce uniqueness and link related data?
Easy31A data analyst creates a line chart showing monthly sales over the past year. The chart uses a y-axis starting at $100,000 instead of zero. What is the most likely misinterpretation a viewer might have?
Easy32A data analyst is preparing to run an A/B test comparing two email subject lines. Which TWO of the following should the analyst define before the test begins?
Medium33In a dataset of employee salaries, the analyst notices one value that is significantly higher than the rest. Using the IQR method, which values are typically considered outliers?
Medium34A retailer wants to test if a new website layout increases the average time spent on the site. They split traffic: control group (old layout) and treatment group (new layout). Which statistical test is most appropriate to compare the average time spent between the two groups?
Medium35A data analyst is performing a hypothesis test with a significance level of 0.05. The p-value obtained is 0.03. What should the analyst conclude?
Medium36A data analyst wants to sample a large dataset of customer transactions. Which TWO sampling methods are probability-based and ensure every element has a known chance of being selected? (Select TWO.)
Medium37A data analyst needs to visualize the relationship between advertising spend and sales revenue for 50 products. Which chart type is most appropriate?
Easy38A data analyst runs an A/B test on a new website layout. The test yields a p-value of 0.04 with the null hypothesis being no difference in conversion rates. The significance threshold is α=0.05. Which of the following is the correct conclusion?
Hard39An analyst needs to retrieve the year from an order_date column (datetime type). Which function should be used in SQL?
Medium40Which TWO of the following are common assumptions of linear regression?
Medium41A business intelligence analyst is designing a dashboard for executives. The dashboard includes revenue, profit margin, and customer satisfaction score. To maximize the data-ink ratio, the analyst should:
Hard42A data analyst needs to combine two datasets: one contains customer information (customer_id, name, address) and the other contains order information (order_id, customer_id, order_date). The analyst wants to include all customers, even those who have not placed orders. Which type of join should be used?
Easy43A data analyst is creating a data story about sales performance. Which THREE elements are essential for effective data storytelling? (Choose THREE.)
Hard44Refer to the exhibit. What does the query return?
Medium45Match each data quality dimension to its description.
Medium46A data analyst is performing a chi-square test of independence on a 2x2 contingency table. The p-value is 0.04. At α=0.05, which THREE of the following statements are correct?
Medium47A dataset contains height measurements in centimeters and inches. An analyst wants to apply k-means clustering. Which data transformation should be applied before clustering?
Medium48A data analyst is testing whether a new website layout increases conversion rate. The p-value from the test is 0.03. Using a significance level of 0.05, what is the correct conclusion?
Hard49A data analyst notices that a column labeled 'Income' contains values like '$50,000' and '$75,000', but also 'High' and 'Low'. What data concept issue is occurring?
Hard50A company is designing a dashboard for real-time monitoring. Which THREE considerations are most critical?
Hard51An analyst needs to display the number of website visitors per age group (e.g., 18-25, 26-35, 36-45). Which chart type is most appropriate?
Medium52A company needs to store user session data for a web application. Each session has a unique session ID, and the data must be retrieved very quickly by session ID. The data does not require complex relationships or transactions. Which type of NoSQL database is most appropriate?
Hard53A data analyst needs to present findings about customer churn to business stakeholders. The analysis identified that churn is highest among customers who have called customer support more than three times in the last month. Which of the following is the best way to communicate this insight?
Easy54A marketing team needs to store customer feedback from social media posts, including text, images, and emojis. Which data concept is most appropriate for this storage?
Easy55In Power BI, a data analyst needs to create a measure that calculates total sales for the current year. Which DAX function should be used?
Hard56Which TWO of the following data quality dimensions are most directly affected by duplicate records?
Medium57A data engineer is designing a data pipeline for a retail company. The source system is an OLTP database that records sales transactions. The target is a data warehouse used for reporting. The engineer is evaluating whether to use ETL or ELT. Which three factors would favor using ELT over ETL? (Select THREE)
Hard58A company uses a NoSQL document database to store product catalogs. Each product document includes fields like product_id, name, category, and price. The operations team frequently queries by product_id and by category. Which type of NoSQL database is being used, and what should be created to optimize queries by category?
Hard59A data scientist is analyzing a dataset with 100 variables and 5,000 records. The dataset has several missing values and a few extreme outliers. The goal is to build a regression model to predict a continuous target. Which combination of preprocessing steps is most likely to improve model performance?
Hard60In a dataset with variables on different scales (e.g., age in years and income in dollars), which preprocessing step is necessary before applying k-means clustering?
Medium61A data analyst at a retail company is building a multiple linear regression model to forecast weekly sales. The dataset contains 50 predictor variables, including store size, promotional spend, holiday indicators, and many others. After training the model, the analyst observes an R-squared of 0.99 on the training set but only 0.55 on the holdout test set. Which action should the analyst take first to address this discrepancy?
Hard62A marketing analyst needs to combine customer data from a CRM database with social media engagement data from a third-party API. Which data acquisition method is most appropriate?
Easy63Which THREE are best practices for acquiring data via web scraping? (Select exactly 3)
Hard64A data analyst is creating a report on customer satisfaction scores across different regions. The analyst wants to highlight regions that are significantly below average. Which of the following statistical methods is most appropriate for identifying these outliers?
Hard65During data profiling, an analyst wants to identify the number of distinct values in a column. Which SQL function should be used?
Medium66Which TWO of the following are characteristics of structured data? (Choose TWO.)
Easy67Which of the following is a characteristic of a NoSQL document database like MongoDB?
Easy68A data analyst is writing a query to rank products by total sales amount within each category. They want ties to have the same rank and no gaps in the ranking sequence. Which window function should they use?
Hard69Which THREE of the following are appropriate methods to handle outliers in a dataset?
Hard70A marketing team wants to collect data on competitor pricing for similar products. Which data source is most appropriate?
Easy71An analyst is preparing data for a clustering algorithm that uses Euclidean distance. Which TWO data preprocessing techniques should be applied to ensure all features contribute equally?
Medium72An analyst calculates a Pearson correlation coefficient of -0.8 between advertising spend and customer churn rate. Which interpretation is correct?
Medium73An analyst needs to aggregate sales data by region and product, then sort the results by total sales in descending order. Which SQL clauses are required? (Select THREE).
Medium74In Tableau, which of the following is used to create a calculated field that aggregates data at a different level of detail than the view?
Easy75A data analyst is creating a dashboard to monitor e-commerce performance. The dashboard will be used by both executives (strategic view) and operations managers (detailed view). The analyst plans to use interactive filters. Which THREE design principles or features are most important to apply for effective dashboard design?
Hard76Match each data governance role to its responsibility.
Medium77A data analyst wants to segment customers into groups based on their purchasing behavior. The dataset includes numerical features such as annual income and purchase frequency. Which algorithm is most appropriate for this task?
Medium78A financial analytics firm needs to acquire historical stock market tick data (millions of records per day) from a data vendor. The vendor provides data via FTP in binary format. The firm's existing infrastructure uses on-premise servers with limited storage and processing power. They need to stream the data into a cloud data lake for analysis. However, the binary format is proprietary and requires a licensed decoder. The budget is constrained. Which approach best meets the data acquisition requirements?
Hard79To consolidate data from multiple operational databases into a central repository for reporting, a company decides to transform data before loading it into the target system. Which data integration approach is being used?
Medium80Refer to the exhibit. Which data quality dimension is being violated?
Hard81When designing a dashboard for executives, which principle is most important to follow to ensure key information is immediately visible?
Medium82Which THREE of the following are NoSQL database types?
Hard83Which TWO of the following are common methods for acquiring data from external sources?
Medium84A healthcare analytics team is building a dashboard to monitor patient vitals. They receive data from two sources: Source 1 provides 'heart rate' as an integer (beats per minute), and Source 2 provides 'blood pressure' as a ratio (systolic/diastolic, e.g., 120/80). The team wants to create a combined metric called 'cardiac stress index' that uses both heart rate and systolic blood pressure. However, they notice that heart rate data occasionally contains negative values due to sensor errors. The data governance policy requires that all data be valid and meaningful. Which action best addresses the data quality issue while preserving the data types?
Medium85A senior data analyst is advising a team on dashboard design principles. Which THREE of the following are recommended best practices? (Choose three.)
Hard86An analyst needs to count the number of orders per customer but only for customers who have placed more than 5 orders. Which SQL construct allows filtering after aggregation?
Medium87A data analyst is creating a data story for a marketing campaign results. Which of the following narrative structures is most effective for engaging the audience?
Easy88Which TWO visualization types are suitable for showing the distribution of a single continuous variable?
Easy89A data analyst needs to design a report for two audiences: executives want a high-level trend, and operational managers need current inventory levels. Which approach best satisfies both?
Hard90A data analyst needs to determine whether the mean sales of two different regions are significantly different. The samples are independent and the data is normally distributed. Which statistical test should be used?
Medium91A data analyst needs to visualize the relationship between two continuous variables, such as sales revenue and advertising spend, to identify potential correlation. Which chart type is most appropriate?
Medium92A data scientist is conducting an A/B test with a significance level of 0.05. Which three factors should be considered when calculating the required sample size? (Choose THREE)
Hard93A dashboard automatically refreshes every hour, but users report stale data. What is the most likely issue?
Medium94In a Power BI report, a data analyst needs to create a measure that calculates the sum of sales only for products that have a profit margin greater than 10%. Which DAX function should be used to filter the calculation?
Hard95A logistic regression model is used to predict the probability of customer churn. The model's coefficient for the feature 'customer support calls' is 0.8 with a p-value of 0.001. Which interpretation is correct?
Hard96In time series decomposition, a data analyst separates a retail sales series into trend, seasonal, and residual components. After decomposition, the residual component shows no pattern and is random. Which of the following best describes the seasonal component?
Hard97A data analyst is preparing a dataset for a predictive model. The dataset contains a feature 'age' with values ranging from 18 to 80, and a feature 'income' ranging from 20,000 to 200,000. To ensure both features contribute equally to distance-based algorithms, which transformation should the analyst apply?
Medium98Refer to the exhibit. What is the impact of the validation result?
Medium99A data analyst calculates the mean, median, and mode of a dataset. Which measure of central tendency is most affected by extreme outliers?
Easy100A retail analyst needs to determine the most popular product category. The dataset includes columns: ProductID, Category, SalesDate, QuantitySold, UnitPrice. Which column contains qualitative data?
Easy101A data analyst is presenting a story about why customer churn increased last quarter. They start by showing the current churn rate, then identify a key event (a pricing change), and finally show the impact of a proposed retention campaign. This structure follows which narrative arc?
Medium102Which TWO are common mistakes when creating data visualizations?
Easy103A retail company wants to identify customer segments based on purchase history and demographics. Which technique is most appropriate for this task?
Medium104In Tableau, an analyst wants to create a parameter that allows users to select a threshold for highlighting products with sales above that value. The parameter is used in a calculated field that returns TRUE if sales exceed the parameter value. Which type of calculated field is this?
Hard105A data scientist is using K-means clustering with k=3. After the first iteration, the centroids are recalculated. Which step occurs next in the algorithm?
Medium106In a multiple regression model, one predictor has a high p-value (0.45). What should the analyst consider doing?
Medium107A data engineer is designing a system to store raw sensor data from thousands of IoT devices. The data is expected to be used for exploratory analytics and machine learning. Which storage solution is most appropriate?
Medium108A data architect is designing a schema for a product catalog where each product has a variable number of attributes. Which NoSQL database type is most appropriate?
Easy109A data analyst is designing a dashboard for non-technical managers. Which TWO design principles should be applied? (Choose TWO.)
Easy110A data analyst needs to join two tables in a SQL database: Orders and Customers. The analyst wants to include all orders, even if there is no matching customer record. Which type of join should be used?
Easy111A data analyst wants to show the correlation between advertising spend and website traffic. Which chart type should they use?
Medium112A business analyst wants to compare the proportion of total sales contributed by each product category in the current year. Which visualization is most suitable?
Medium113A data analyst is examining the distribution of customer ages in a dataset. The ages are: 22, 25, 29, 30, 31, 34, 35, 37, 40, 42, 45, 50, 55, 60, 65. Which measure of central tendency would be least affected by an outlier if a value of 120 is incorrectly recorded as age 120?
Medium114A data analyst wants to show the sales trend for a product over the past 12 months. Which chart type is most appropriate?
Easy115A data scientist is merging retail transaction data from online and in-store sources. Which THREE steps are required to ensure data consistency?
Hard116A company is implementing a centralized reporting layer to replace departmental spreadsheets. Which TWO benefits are most directly achieved?
Easy117A data engineer needs to acquire data from a legacy mainframe system that does not support modern APIs or direct database connectivity. Which approach is most feasible?
Hard118A data analyst is creating a dashboard to display monthly sales trends for the past two years. The dataset includes monthly sales figures with seasonal fluctuations. The analyst wants to highlight both the overall trend and the seasonal patterns effectively. Which TWO chart types are most appropriate for this purpose? (Select two.)
Medium119In a multiple regression model with three predictors, the coefficient for one predictor is 5.2 with a p-value of 0.001. Which of the following is the best interpretation?
Hard120Refer to the exhibit. A data analyst wants to create a visualization that best shows the trend of sales over time for each department. Which chart type should be used?
Easy121A marketing manager wants to visualize the conversion rate at each stage of a sales funnel, from leads to closed deals. The data shows the number of prospects at each stage. Which chart type is most appropriate for this pipeline analysis?
Medium122A data analyst is presenting a complex statistical analysis to a group of data scientists. The audience is highly knowledgeable. Which TWO approaches are most appropriate? (Choose two.)
Hard123A company wants to determine if there is a significant difference in the average sales revenue between two different store layouts. They collect sales data from 30 stores with Layout A and 30 stores with Layout B. Which statistical test is most appropriate for comparing the means of these two independent groups?
Medium124A data analyst is preparing a data storytelling presentation for a non-technical audience. Which THREE techniques are most effective for communicating insights?
Medium125A sales manager wants to display the contribution of each product category to total revenue, with a maximum of six categories. Which chart type is most suitable?
Medium126A database has a table 'Orders' with columns OrderID (PK), CustomerID, OrderDate, and a table 'OrderDetails' with OrderID (FK), ProductID, Quantity. To ensure that every OrderID in OrderDetails exists in Orders, which integrity constraint is enforced?
Hard127A sales dashboard shows monthly revenue but the bars are very tall for some months and very short for others, making comparisons difficult. Which visualization modification would best improve readability?
Medium128A data analyst is troubleshooting a map visualization that shows null values for some regions. Which TWO actions should the analyst take to resolve the issue?
Hard129A data analyst is creating a presentation for the board of directors. The board members have varying levels of data literacy. The analyst wants to ensure that the key insight—that customer satisfaction scores have declined by 15% due to longer wait times—is understood by everyone. Which approach is best?
Hard130An analyst creates a bar chart showing average sales by region. They want to ensure that the y-axis starts at zero to avoid misleading interpretation. This practice aligns with which dashboard design principle?
Medium131A logistics company receives GPS tracking data from fleet vehicles at 1-second intervals via a cellular network. The data is used to optimize routes and monitor driver behavior. Recently, the data acquisition system has been missing updates for some vehicles when they pass through tunnels or remote areas. The data team notices gaps during these periods. The company needs a solution to ensure near-real-time data continuity. What should they do?
Medium132An organization uses a data warehouse for analytics. Which two characteristics are typical of a data warehouse compared to a data lake? (Select TWO.)
Hard133A time series dataset has several missing months of data. Which chart type will present the most honest picture of the trend?
Hard134A data analyst needs to present the results of a customer segmentation analysis to the marketing team. The analysis identified four segments based on purchasing behavior. Which visualization is most effective for showing the characteristics of each segment?
Easy135A data scientist builds a logistic regression model to predict customer churn (yes/no). The model outputs a probability of 0.75 for a particular customer. Which of the following best describes this output?
Hard136A company's database has a table 'orders' with columns: order_id, customer_id, order_date, and total_amount. A data analyst needs to identify customers who have placed more than 5 orders in the past year. Which data concept should be used to group orders by customer and count them?
Medium137A data team is communicating findings from a machine learning model that predicts equipment failure. The model has high accuracy but low recall. Which of the following statements is the most accurate way to communicate the model's performance to the maintenance team?
Hard138A retail company is migrating its on-premises data warehouse to a cloud data warehouse. The current ETL process extracts data from a transactional database (SQL Server) and a web analytics system (JSON logs). The ETL runs nightly and takes 6 hours. The business requires that the new cloud warehouse support real-time reporting with data latency of less than 15 minutes. The data engineer proposes using change data capture (CDC) from the SQL Server database and streaming the JSON logs via a message queue. However, management is concerned about cost and complexity. The engineer must design a solution that meets the latency requirement while minimizing operational overhead. Which approach should the engineer recommend?
Medium139A data analyst is using pandas in Python to clean a dataset. Which method is most appropriate to replace missing numerical values with the median of the column?
Medium140A data analyst at a marketing firm is tasked with segmenting customers based on their purchasing behavior. The dataset contains 10,000 customers with features such as annual spend, frequency of purchases, recency of last purchase, and average order value. The analyst decides to use k-means clustering. After standardizing the features, the analyst runs k-means with k=3, k=4, and k=5, and computes the silhouette score for each: k=3: 0.45, k=4: 0.52, k=5: 0.48. The analyst also plots the elbow curve and observes that the within-cluster sum of squares (WCSS) decreases sharply from k=2 to k=4, then levels off. Based on these results, what is the most appropriate number of clusters?
Medium141Which TWO of the following chart types are appropriate for showing the distribution of a continuous variable? (Choose 2.)
Medium142A data analyst is evaluating data quality for a customer database. Which TWO dimensions of data quality are most directly affected by duplicate customer records?
Medium143A data analyst is tasked with extracting data from a legacy system that outputs fixed-width text files. The analyst needs to parse these files into a structured format. Which tool or method is most appropriate for this task?
Medium144A data analyst is creating a weekly KPI email for executives. Which TWO attributes are most important for this type of report?
Medium145A data analyst is creating a dashboard for a retail company. Which TWO of the following are considered Key Performance Indicators (KPIs) tied to strategic objectives?
Medium146A data analyst is presenting a time-series chart of monthly sales to executives. The sales dropped sharply in March due to a one-time supply chain disruption. Which storytelling technique would best help the audience understand this anomaly?
Hard147Drag and drop the steps to conduct a hypothesis test in the correct order.
Medium148A data analyst needs to sample 1000 customers from a database of 100,000 customers for a survey, ensuring every customer has an equal chance of selection. Which sampling method is most appropriate?
Medium149A data analyst is tasked with visualizing the distribution of customer ages across different regions. The dataset contains outliers. Which chart type best displays the distribution and highlights outliers?
Medium150A data analyst needs to retrieve current weather data from a third-party service. The service provides an endpoint that returns data in JSON format over HTTP. Which data source type is being used?
Medium151During data acquisition, an analyst notices that the data from an external vendor has inconsistent date formats. What is the first step the analyst should take?
Medium152A business analyst is creating a dashboard to monitor sales performance. The primary goal is to quickly identify which regions are underperforming compared to the target. Which design principle is most important to apply?
Medium153An analyst creates a pie chart showing market share of four companies: A (45%), B (30%), C (15%), D (10%). A stakeholder complains that it is difficult to compare C and D. Which alternative chart should the analyst recommend?
Easy154A dashboard designer is building a sales performance dashboard for executives. According to dashboard design principles, which TWO practices should be applied? (Choose two.)
Easy155A data analyst needs to extract data from a transactional database and load it into a data warehouse for reporting. Which process typically transforms the data before loading it into the warehouse?
Medium156A data analyst is presenting a story to executives about a decline in sales. The analyst wants to show the key events that led to the decline, such as a product recall and a competitor's launch. Which storytelling technique should be used?
Hard157A company needs to store raw data from IoT sensors for future machine learning projects. The data is expected to be massive and in various formats. Which storage solution is most appropriate?
Medium158A data analyst wants to show the proportion of total sales for each product category. There are 4 categories. Which chart type is most appropriate?
Easy159Which THREE of the following are best practices when performing data extraction for a data pipeline?
Hard160During a data presentation, an audience member questions the accuracy of the data shown. Which of the following is the best way for the analyst to respond?
Medium161A data warehouse team is considering moving from an ETL to an ELT approach. Which THREE of the following are advantages of ELT over ETL?
Hard162A dataset contains the ages of 100 customers. The analyst wants to transform the ages to a 0-1 range for use in a distance-based algorithm. Which technique should be used?
Easy163Which TWO actions are best practices for creating effective data visualizations?
Medium164A data analyst runs the Python code shown. What is the result of executing this code?
Easy165A data analyst is cleaning a dataset and finds missing values in a categorical variable representing customer region. Which imputation method is most appropriate?
Easy166A data analyst needs to identify duplicate customer records based on email and phone number. Which SQL techniques can be used to find duplicates? (Select TWO).
Medium167A data analyst is comparing characteristics of structured and unstructured data. Which TWO of the following are characteristics of structured data? (Choose two.)
Medium168Refer to the exhibit. A data analyst is troubleshooting a failed dashboard refresh. The error log shows repeated SQL syntax errors. Which of the following is the most likely cause?
Medium169A data analyst needs to visualize the relationship between two continuous variables: advertising spend (in dollars) and monthly sales (in units). Which chart type is most appropriate?
Easy170Match each data visualization type to its best use case.
Medium171Refer to the exhibit. A data analyst receives this error when running a data load script. What is the most likely cause?
Medium172A data analyst wants to randomly select 100 customers from a database for a survey, ensuring that the sample reflects the proportion of male and female customers in the population. Which sampling method is most appropriate?
Medium173A marketing manager wants to visualize the conversion funnel from website visits to final purchase. Which chart type is most appropriate?
Medium174Which data sampling method involves selecting every k-th element from a list after a random start?
Easy175A data analyst is extracting data from a relational database using SQL. Which clause is essential for limiting the rows retrieved to only those needed?
Easy176An analyst is conducting an A/B test on a new website layout. Which TWO of the following must be defined before the test begins?
Hard177A financial institution is merging transaction data from two different systems. System A stores currency amounts as integers in cents, and System B stores as decimals in dollars. What is the best way to integrate the data?
Hard178A social media monitoring company collects public tweets using the Twitter API. The API has a tiered access: free tier allows 500,000 tweets per month, and paid tier allows 2 million tweets per month. The company needs to collect 1.5 million tweets per month for analysis. They are on a free tier but have been exceeding the limit, causing account suspension. They need a sustainable solution without significantly increasing costs. What should they do?
Hard179A data scientist is building a model to predict customer churn. The company's internal CRM system provides customer demographics and transaction history. They also purchase demographic data from a third-party vendor. How should the purchased data be classified?
Medium180A data analyst needs to visualize the distribution of customer ages in a dataset. The analyst wants to see the frequency of ages grouped into bins. Which chart type should be used?
Medium181A data engineer is designing a data pipeline where raw data is loaded into a cloud data warehouse (Snowflake) and then transformed using SQL. This approach is called:
Hard182A stakeholder asks for the exact number of customers who churned last month. Which metric should the analyst report?
Medium183Which THREE of the following are common mistakes when creating data visualizations? (Choose 3.)
Hard184Which TWO color choices are appropriate for a categorical data visualization? (Select two.)
Easy185A business user asks a data analyst to include several charts in a weekly report. The user wants to see the trend of sales over the last 12 months at a glance. Which chart type should the analyst use?
Easy186Which SQL function can be used to extract the year from a date column 'order_date'?
Easy187A data analyst is performing data profiling on a customer table. Which TWO metrics are most useful for understanding the completeness of the data? (Choose two.)
Medium188A company needs to visualize monthly sales revenue for the past five years to identify seasonal trends. Which chart type is most appropriate?
Medium189An organization is implementing a centralized reporting layer to replace multiple departmental spreadsheets. Which governance principle does this support?
Hard190An analyst needs to identify outliers in a numeric column 'transaction_amount' using the interquartile range (IQR) method. Which TWO steps are part of this process? (Select TWO).
Medium191You are analyzing sales data and need to calculate the moving average of monthly sales over the previous 3 months for each month. Which type of function is best suited for this task?
Medium192A data analyst needs to communicate findings to a non-technical audience that is concerned with overall performance but not interested in details. Which approach is best?
Easy193A sales report shows a 10% increase in revenue, but the analyst knows the data has limitations. Which TWO elements should be included to communicate uncertainty? (Select TWO.)
Medium194A marketing team runs an A/B test comparing two webpage designs. The null hypothesis states there is no difference in conversion rates. The p-value is 0.08 at α=0.05. Which is the correct interpretation?
Medium195Which measure best describes the spread of the middle 50% of a dataset?
Easy196A data analyst is performing data profiling on a customer dataset. Which metric would best reveal the number of distinct values in the 'state' column?
Medium197An analyst uses K-means clustering on customer purchase data. After plotting the within-cluster sum of squares for different values of k, they observe an elbow at k=4. What is the most appropriate number of clusters?
Medium198A data analyst needs to visualize the distribution of customer ages in a dataset containing 10,000 records. The analyst wants to see the shape of the distribution and identify any outliers. Which chart type is most appropriate?
Medium199A dataset has missing values in the 'age' column. The distribution of age is approximately normal with few outliers. Which imputation method is most appropriate?
Medium200An analyst is creating a Tableau dashboard for a logistics company. They need to allow users to filter data by region and time period, and also want to show a tooltip with detailed shipment information. Which THREE Tableau features should be used? (Choose three.)
Hard201Which chart type is best for displaying the distribution of a continuous variable, such as the age distribution of customers?
Easy202A data analyst is comparing the average test scores of students who attended a tutoring program versus those who did not. Which statistical test is most appropriate for determining if there is a significant difference between the means of these two independent groups?
Easy203A dashboard uses a heatmap to show sales density by hour and day of week. Users report that the color scale is confusing because some low values appear similar to high values. Which design change improves clarity?
Medium204Which THREE data quality dimensions are commonly assessed in a data profiling task?
Hard205Which TWO of the following are considered structured data?
Medium206In Looker Studio, a data analyst has two data sources: one with customer IDs and transactions, and another with customer demographics. They need to create a chart that includes fields from both sources. Which feature should they use?
Hard207Match each data sampling method to its description.
Medium208A data analyst is creating a report to compare the performance of different sales regions. The report will be used by regional managers to identify areas needing improvement. Which of the following visualization techniques would be most effective?
Medium209In a linear regression model predicting house prices, the coefficient for the number of bedrooms is $30,000 and the intercept is $50,000. If a house has 3 bedrooms, what is the predicted price?
Hard210Which report type is best suited for monitoring the real-time status of manufacturing equipment on the factory floor?
Easy211A data analyst wants to create a temporary result set that can be referenced within a single SQL statement. Which feature should be used?
Easy212A data team is designing an ETL process to extract data from an operational database daily. The database experiences heavy write loads during business hours. What is the best practice to minimize impact on operations?
Medium213In time series analysis, which component represents regular patterns that repeat over fixed periods, such as daily or yearly?
Medium214A data analyst receives a request from a sales manager for a one-time report on Q4 performance by product line. The report is not expected to be repeated. Which type of report should the analyst create?
Medium215After a marketing campaign, sales increased by 15%. The analyst wants to understand which customer segment contributed most to the increase. Which type of analysis is this?
Easy216A business analyst is asked to distinguish between KPIs and metrics for a new dashboard. According to CompTIA Data+, which TWO statements correctly differentiate KPIs from metrics? (Choose two.)
Medium217A marketing analyst needs to answer a one-time question about campaign performance for a specific week. Which report type is appropriate?
Medium218A data engineer is designing a data warehouse for a retail company. The fact table must record each sale transaction, including product ID, store ID, date, and quantity sold. The product details (name, category, price) are stored in a separate table. This design is an example of which data modeling concept?
Medium219A data analyst is designing a dashboard for executives. Which best practice should be followed regarding the placement of key performance indicators (KPIs)?
Easy220An e-commerce company stores customer support emails in a text database, product images in a blob store, and sales transactions in a SQL table. Which data store holds only structured data?
Hard221A data analyst wants to concatenate first_name and last_name columns with a space in between. Which string function combination should be used in SQL?
Medium222A data analyst is performing data profiling on a customer table. Which TWO of the following are key metrics to assess data quality? (Select TWO.)
Medium223Which THREE of the following are components of Master Data Management (MDM)? (Select 3)
Medium224A data scientist is building a K-means clustering model for customer segmentation. After plotting the within-cluster sum of squares (WCSS) against the number of clusters (k), she observes that the WCSS decreases sharply until k=5 and then levels off. Which value of k should she choose based on the elbow method?
Hard225A data analyst wants to visualize the distribution of customer ages, including quartiles and potential outliers, for a dataset with 10,000 records. Which TWO chart types are appropriate? (Choose two.)
Medium226Drag and drop the steps to create a data visualization dashboard in the correct order.
Medium227A data analyst needs to combine customer data from a MySQL transactional database with product data from a MongoDB document store to create a unified view for reporting. The analyst uses a SQL query that joins the tables after extracting data from both sources. Which database concept is being applied?
Hard228Which TWO of the following are commonly used techniques for handling missing data in a dataset? (Select TWO).
Medium229A data analyst is designing a self-service reporting platform for business users. Which TWO practices will help ensure data consistency and trust? (Select TWO.)
Medium230A financial analyst needs to show how net income is derived from revenue, costs, and expenses over a period. The chart should highlight the contribution of each component. Which chart type is most appropriate?
Medium231Which database concept ensures that data in one table corresponds to data in another table, preventing orphan records?
Medium232A data analyst creates a dashboard showing average order value by region. The chart indicates that one region has an unusually high average. Investigation reveals that the region has very few orders, but one large purchase inflates the average. Which data transformation should the analyst apply to improve the visualization?
Medium233A data analyst creates a dashboard that includes a map showing sales by region. The map uses a continuous color gradient from light yellow to dark blue. Some regions with very high sales appear as dark blue, but many regions with moderate sales appear similar. Which improvement would most enhance the readability?
Medium234Which TWO are common pitfalls when communicating data insights?
Easy235A data analyst is pulling data from a production database for a report. The database contains customer orders with a column 'order_date'. The analyst notices that some orders have dates in the future. Which data quality issue does this represent?
Medium236A business user wants to explore sales data by creating custom charts and tables without writing SQL queries. Which type of report capability should the BI team provide?
Easy237Refer to the exhibit. Based on the data profiling results, what is a likely data quality issue?
Hard238A data analyst is preparing a dataset for a machine learning algorithm that assumes normally distributed features. Which TWO data transformation methods should the analyst consider to achieve this?
Medium239A retail company with 500 stores across North America wants to visualize its sales performance. The dataset includes store ID, region (Northeast, Southeast, Midwest, West), product category (Electronics, Clothing, Home Goods), monthly sales (in dollars), and date (from January 2018 to December 2023). The data has missing values for about 5% of store-month combinations, and a few stores have reported sales that are 10 times higher than the average for their region due to grand opening events. The goal is to create a dashboard that shows monthly sales trends for each region and product category, and allows users to identify which categories are driving growth. Which approach should the analyst take?
Medium240A dataset contains employee salaries ranging from $30,000 to $200,000. An analyst wants to scale the salaries to a range of 0 to 1 for use in a distance-based clustering algorithm. Which method should they use?
Medium241In a table 'employee_hierarchy' with columns 'employee_id', 'manager_id', and 'employee_name', an analyst needs to generate a list of all employees under a specific manager, including multiple levels of subordinates. Which SQL construct is most appropriate for querying this hierarchical data efficiently?
Hard242A healthcare organization acquires data from multiple hospitals with different patient record systems. The data includes patient IDs but no common identifier across systems. Which technique should be used to link records?
Medium243Which SQL aggregate function would an analyst use to calculate the average value of a numeric column?
Easy244An organization wants to assign responsibility for data quality and metadata management. Which role is primarily accountable for defining data standards and ensuring data quality across a specific domain?
Easy245A data analyst creates a dashboard for executives to monitor quarterly sales. Which best practice ensures the dashboard is effective?
Easy246A research firm is acquiring data from public government databases via API. The API rate limits at 100 requests per minute. They need to download 10,000 records, but each request returns a maximum of 100 records. What is the most efficient approach to ensure complete acquisition without being blocked?
Hard247A data analyst needs to create a visual that shows the distribution of customer ages across different regions. Which chart type is most appropriate?
Easy248During a presentation, a stakeholder questions the validity of a correlation found. What is the best response?
Hard249A healthcare organization is building a data warehouse to support population health analytics. The data sources include: (1) an electronic health record (EHR) system with a relational database containing patient demographics, diagnoses, and medications; (2) a claims system that generates CSV files daily; (3) patient-generated health data from mobile apps via a REST API returning JSON. The data engineer needs to design a data acquisition process that runs nightly. The EHR system has a change tracking mechanism that logs changes with timestamps. The claims CSV files are appended daily. The API supports filtering by date. The data warehouse uses a star schema with fact and dimension tables. The engineer must ensure data consistency and minimize load times. Which approach should the engineer take?
Hard250In an A/B test, the null hypothesis states that there is no difference between the conversion rates of the control and treatment groups. After collecting data, the p-value is 0.03. Using a significance level α = 0.05, what should the analyst conclude?
Easy251Which of the following data sources is most likely to generate streaming data?
Easy252A financial report must be retained for seven years to comply with regulatory requirements. This is an example of which data governance principle?
Medium253A data analyst receives a dataset with a column 'salary' that contains values like '45,000', '55,000', and '65,000'. The analyst notices that the values are stored as text. Which data concept should be applied to convert the salary column from text to numeric format for analysis?
Easy254A researcher wants to study the effect of a new drug. She collects data directly from clinical trial participants. Later, she compares her findings with historical data from medical journals. Which contrast best describes her data sources?
Medium255Which TWO of the following are best practices when presenting data insights to a non-technical audience?
Easy256An analyst needs to combine two datasets from different sources that share a common key but have different levels of granularity. Dataset A has daily sales per store, Dataset B has hourly foot traffic per store. The analyst wants to analyze correlation. Which approach is appropriate?
Medium257A data analyst is designing a dashboard for senior executives who need to quickly monitor key business metrics. Which TWO design principles should the analyst follow? (Choose two.)
Easy258A data analyst uses Python's pandas library to read a CSV file into a DataFrame. Which function is used to read the file?
Easy259A data analyst is designing a data model for a sales data warehouse. The model should optimize query performance for aggregations by minimizing joins and duplicating data where necessary. Which schema design should the analyst use?
Easy260A dashboard designer wants to ensure that the most important metric, such as total revenue, is prominently displayed at the top left. Which dashboard design principle is being applied?
Medium261A data analyst uses linear regression to model the relationship between advertising spend and sales. The residual plot shows a clear U-shaped pattern. What assumption is violated?
Hard262In a sales database, an analyst needs to retrieve all orders where the order amount is between $100 and $500. Which WHERE clause should be used?
Easy263A BI analyst is creating a report in Power BI and needs to calculate the total sales for the current year compared to the previous year. Which DAX function should be used to calculate the previous year's sales?
Medium264A company requires real-time masking of credit card numbers for customer support agents while allowing full access for accountants. Which technique should be implemented?
Medium265A data architect is designing an ETL pipeline to ingest streaming data from IoT sensors. The data must be available for real-time analytics. Which acquisition method is best?
Hard266Refer to the exhibit. A data analyst is reviewing the configuration of an executive dashboard. The dashboard refreshes daily at 6:00 AM. Which of the following best describes a potential issue with this dashboard for executive use?
Hard267A healthcare analytics team is building a predictive model to identify patients at high risk of readmission within 30 days of discharge. The dataset includes 50,000 patient records with 200 features, including demographics, vital signs, lab results, and historical admissions. The target variable is binary (readmitted or not). The team uses a logistic regression model and achieves an AUC of 0.72 on the test set. However, the model's calibration is poor: for patients predicted to have a 70% risk, the actual readmission rate is only 40%. The team wants to improve calibration without significantly reducing discrimination (AUC). The data scientist suggests applying Platt scaling. However, the team lead is concerned that Platt scaling may reduce the model's ability to rank patients correctly. Which of the following is the best course of action?
Hard268A data scientist is performing a hypothesis test with a significance level α=0.05. The p-value obtained is 0.03. What should the scientist conclude?
Medium269A healthcare analytics team is building a classification model to predict patient readmission within 30 days. The dataset contains 10,000 records with 30 features, including demographics, vital signs, lab results, and medication history. The target variable is imbalanced: 85% no readmission, 15% readmission. The team used logistic regression with default settings and achieved an accuracy of 85%, but the model predicted 'no readmission' for all patients. The lead analyst suspects the model is not learning due to class imbalance. The team has time to implement one corrective action before the next model review. Which action should the team take?
Medium270Which TWO of the following are components of time series data?
Medium271A logistics company tracks delivery times and customer satisfaction scores. The data analyst finds that delivery times have increased over the past quarter, correlating with a drop in satisfaction. The analyst needs to present this to the operations team, which is interested in root cause analysis. The team wants to identify whether the increase is due to specific regions, routes, or time periods. The analyst has access to granular data including timestamps, route IDs, and region codes. The presentation should lead to actionable insights for process improvement. What visualization should the analyst use as the primary chart?
Medium272A data analyst is designing a dashboard for a sales team. Which TWO of the following are best practices for dashboard design?
Easy273Which THREE of the following are appropriate ways to handle outliers when communicating data insights?
Hard274A retail company stores customer purchase history in a relational database. The database contains a table 'transactions' with columns: transaction_id, customer_id, product_id, quantity, price, and transaction_date. A data analyst needs to create a report that shows total revenue per customer for the last quarter. Which data concept describes the relationship between customer_id and total revenue?
Medium275An organization needs to acquire data from a third-party vendor. The data will be used for regulatory reporting. Which of the following should be the primary consideration before acquiring the data?
Hard276A data analyst wants to understand the relationship between advertising spend and sales revenue. The analyst calculates a Pearson correlation coefficient of 0.85. Which of the following is the best interpretation?
Medium277A data analyst wants to retrieve the top 5 highest-paid employees from an 'employees' table, including ties. Which SQL clause should be used?
Medium278A data analyst is building a dataset from multiple sources and needs to ensure data quality. During the data acquisition phase, which activity is most important to perform?
Medium279A company is analyzing customer feedback sentiment. The dataset is highly imbalanced with 95% positive and 5% negative comments. Which technique should the analyst use to address class imbalance before modeling?
Hard280A data analyst is designing a dashboard for a sales team. Which TWO of the following are key performance indicators (KPIs) rather than operational metrics?
Medium281Which TWO of the following are measures of central tendency?
Easy282A company's sales report shows revenue of $1.2M, but the calculation method is unclear. What data governance artifact would clarify the definition?
Medium283In Looker Studio, you have a data source with daily sales and a separate data source with marketing spend. You want to create a chart that shows sales and marketing spend on the same axis, but the two sources are not joined natively. Which feature should you use to combine them?
Hard284A data analyst wants to find the top 5 products by total sales amount, but only for products that have been sold more than 50 times. Which SQL query accomplishes this?
Medium285Which THREE are challenges in acquiring data from external sources? (Select three.)
Hard286A data analyst is creating a dashboard in Looker Studio and needs to combine data from two different data sources using a common field. Which feature should be used?
Medium287A data analyst needs to sample 10% of customers from each of three regions (North, South, Central) to ensure proportional representation. Which sampling method should be used?
Medium288Which THREE of the following are examples of descriptive statistics? (Select THREE.)
Easy289A retail company's data analyst developed a dashboard for store managers to monitor daily sales performance. The dashboard includes numerous metrics such as sales by hour, product category, employee, and customer demographics, along with trend lines and forecast graphs. Despite the comprehensive data, store managers are ignoring the dashboard because they find it cluttered and confusing. They prefer to rely on their intuition and verbal updates from shift leads. The analyst needs to improve communication of data insights to ensure the dashboard is used effectively. Which of the following actions should the analyst take FIRST?
Medium290A data analyst wants to use a Z-score to standardize a dataset. The variable has a mean of 50 and a standard deviation of 10. What is the Z-score for a raw value of 70?
Easy291Which chart type is best for visualizing the correlation between two continuous variables?
Easy292A data analyst receives a file with the extension .json. This file contains product information with attributes that vary between records. How should this file be classified?
Easy293A data analyst notices that the sales numbers in a report differ from the numbers in the finance department's spreadsheet. This discrepancy is most likely due to a lack of:
Easy294A data analyst notices that a dataset of customer ages has several missing values. Which method for handling missing data is most appropriate if the data is missing completely at random and the analyst wants to preserve sample size?
Medium295A dataset contains a 'salary' column. The analyst wants to identify outliers using the IQR method. If Q1 = 40,000 and Q3 = 70,000, what is the upper threshold for a non-outlier?
Medium296An organization is implementing a data warehouse to support business intelligence reporting. The data warehouse must ensure that transactions are processed reliably. Which property guarantees that each transaction is treated as a single, indivisible unit?
Medium297A data analyst is cleaning a dataset with missing values. Which TWO of the following are acceptable methods for handling missing numerical data?
Easy298The exhibit shows a SQL query result intended for a bar chart of revenue by region. However, the chart shows only the top 10 regions, but the query returns all regions. What is the most likely cause?
Hard299A manager in operations needs a real-time dashboard showing production line status, including machine uptime and error counts. Which type of report is most appropriate?
Medium300A data analyst needs to retrieve all unique job titles from the employees table. Which SQL clause should be used with the SELECT statement?
Easy301A data analyst is building a logistic regression model to predict whether a customer will churn (yes/no). Which TWO statements about logistic regression are correct?
Hard302A table 'orders' contains columns 'order_id', 'customer_id', 'order_date', and 'total'. An analyst needs to find orders placed between January 1, 2023 and December 31, 2023. Which WHERE clause is correct?
Easy303In Tableau, an analyst wants to create a calculated field that returns the average sales per customer only for customers who have made more than five purchases. Which Tableau function or approach would be most efficient?
Medium304Which TWO of the following are valid techniques for validating the performance of a predictive model?
Hard305A company's sales dashboard shows that the current month's revenue is $1.2M, which is 10% below the target of $1.33M. The analyst wants to highlight this shortfall. Which method of data presentation is most effective?
Medium306An analyst runs a simple linear regression with an R² value of 0.85. Which interpretation is correct?
Medium307A data governance team is drafting a policy for handling personally identifiable information (PII). According to data governance best practices, which document should define the classification levels and handling procedures?
Hard308A data analyst creates a dashboard for operational metrics. The operations team reports that the dashboard is confusing because it shows too many metrics on one screen. Which design principle should the analyst apply?
Medium309A data analyst wants to identify customers whose last name starts with 'Mc' from the 'customers' table. Which WHERE clause condition should be used?
Easy310An analyst builds a dashboard with a gauge showing 'Current Inventory Level' as a percentage. Stakeholders find the gauge misleading because it always shows near 100% even when inventory is low. What is the most likely issue?
Medium311A data analyst needs to communicate the findings of a marketing campaign analysis to the Vice President of Marketing. The VP typically only reads the first paragraph and wants the key takeaway immediately. Which format should the analyst use?
Easy312An analyst is performing K-means clustering on customer data. The elbow method shows a clear bend at k=4. Which THREE of the following are true about K-means clustering with k=4?
Hard313A data analyst needs to present findings to a non-technical executive audience. Which visualization type is most appropriate to communicate a clear comparison of sales performance across multiple regions for the current quarter?
Medium314A large financial institution is implementing a data governance framework to comply with new regulations requiring strict control over sensitive customer data. The data governance committee has identified several domains, including customer master data, transaction data, and risk assessment data. They need to decide on a master data management (MDM) approach that ensures a single, authoritative source of customer information across all systems. However, the current environment has multiple legacy systems with conflicting customer records. The committee is concerned about downtime and business disruption during the transition. Which MDM approach best balances data consistency with minimal operational impact?
Hard315A marketing analyst wants to predict whether a customer will churn (yes/no) based on account age and monthly charges. Which regression technique is most appropriate?
Medium316A data analyst is investigating a correlation between two continuous variables. Which THREE of the following are appropriate steps in this exploratory data analysis? (Select THREE.)
Hard317An organization wants to ensure that all reports use the same definitions for metrics like 'Active Customer' to avoid confusion. Which data governance element should be implemented?
Hard318A data scientist is analyzing a dataset with multiple features and wants to apply k-means clustering to segment customers. She chooses k = 4 based on the elbow method. During the iteration process, which of the following correctly describes a step in the k-means algorithm?
Hard319Refer to the exhibit. Which type of ensemble method is being used?
Medium320A healthcare analyst is creating a report on patient outcomes. To comply with privacy regulations, which action should be taken before publishing?
Medium321A data analyst is reviewing a SQL query that joins three large tables. The query takes over an hour to run. The analyst notices that the WHERE clause filters on indexed columns in only two tables. Which of the following should the analyst do first to improve performance?
Medium322A data team is creating a dashboard to monitor real-time sales. What design principle is critical?
Medium323A data analyst is working in Looker Studio and wants to add a metric that counts the number of unique customers per month. In the context of Looker Studio, which type of field is this metric?
Medium324An analyst compares average sales across three different store locations using a statistical test. Which test is most appropriate?
Medium325An analyst finds that a key metric drops significantly after a data pipeline update. How should the analyst proceed?
Hard326A data analyst wants to compare the total sales of four different product categories for a single year. Which chart type is most appropriate for this comparison?
Easy327A retail company stores customer transaction data in a relational database. They want to analyze purchasing patterns over time. Which type of data structure best supports this analysis?
Easy328During a data mining project, an analyst discovers that a significant number of records have a negative value for the age field. What is the most appropriate first step?
Hard329A data analyst is evaluating the quality of a customer database. Which THREE of the following are dimensions of data quality?
Hard330A data analyst at a marketing agency is working with a dataset containing customer demographics, purchase history, and social media engagement metrics. The agency wants to perform sentiment analysis on unstructured social media comments to identify brand perception. The dataset also includes structured fields like age, income, and purchase amounts. The analyst needs to choose a storage and processing platform that can handle both structured and unstructured data efficiently without requiring extensive schema definition upfront. Which platform should the analyst recommend?
Easy331Which data quality dimension ensures that data represents the real-world object or event correctly?
Easy332A data analyst is building a dashboard in Tableau and wants to allow users to select a specific product category and have all charts on the dashboard filter to that category. Which Tableau feature should be used?
Medium333Which of the following is a characteristic of structured data?
Easy334A data analyst is performing time series analysis on monthly sales data and notices a consistent pattern of higher sales every December. Which component of time series does this represent?
Medium335A data analyst is merging two datasets from different departments. The analyst notices that the 'CustomerID' field in the first dataset is stored as an integer, while in the second dataset it is stored as a string with leading zeros. Which TWO steps should the analyst take to ensure successful data integration?
Medium336In a table 'sales_team' with columns 'salesperson', 'quarter', and 'revenue', an analyst wants to assign a rank to each salesperson within their quarter based on revenue, with the highest revenue getting rank 1. However, if two salespeople have the same revenue, they should receive the same rank, and the next rank should be the next consecutive integer (no gaps). Which window function should be used?
Hard337Refer to the exhibit. What is the most likely issue causing the unexpectedly low count?
Medium338A company ingests customer clickstream data from its website. The data arrives continuously in JSON format and must be stored for real-time analytics. Which type of data source is being described?
Medium339A data analyst is exploring a sales dataset and wants to identify columns that are likely to be foreign keys. Which TWO characteristics would indicate a foreign key?
Medium340A data analyst is cleaning a dataset and identifies several outliers. Which TWO methods are appropriate for handling outliers?
Hard341A data team created a dashboard for executives. The dashboard updates daily and includes several KPIs. Executives complain that they cannot quickly identify the most critical issues. Which design change would best address this?
Medium342A data analyst is examining sales data for a retail chain and notices that the mean monthly sales is $50,000 while the median is $35,000. Which of the following best describes the distribution of the sales data?
Medium343A financial institution needs to acquire credit transaction data from multiple sources while ensuring compliance with data privacy regulations. What is the most critical step?
Hard344A company receives daily sales data in CSV format. The data includes a 'Date' column in MM/DD/YYYY format. To load this into a database that expects YYYY-MM-DD, the analyst should:
Easy345A retail company is acquiring sales data from 150 stores worldwide. Each store sends daily CSV files via email to a central email address. The data acquisition process is manual: an intern downloads each attachment and copies it into a shared folder. The shared folder is then accessed by an ETL tool that loads data into a data warehouse. Recently, the data warehouse has been missing records for several stores. The intern reports that some emails are not being received or are delayed. The company needs to improve the reliability and timeliness of data acquisition. Which course of action should be taken first?
Hard346When presenting data insights to a technical audience, which of the following is most important to include?
Medium347An executive dashboard needs to display key performance indicators (KPIs) such as sales growth and customer satisfaction. Which design principle is most important?
Medium348A data analyst is building a report in Power BI and needs to create a measure that calculates the total sales for the current year, but only for products that have at least one sale in the previous year. Which DAX function combination is most appropriate?
Hard349Refer to the exhibit. A data analyst notices that direct S3 access to files outside the "incoming/" prefix is blocked. Which data governance principle does this policy enforce?
Medium350A data analyst is evaluating data quality issues during acquisition. Which TWO issues are most likely to arise from merging data from different sources? (Select exactly 2)
Medium351A data analyst includes a map showing customer locations by zip code. The map reveals exact addresses for a few customers due to data granularity. This violates which principle?
Hard352A data audit reveals that some numbers in the "Revenue" column were manually entered from PDF invoices. This introduces potential errors. Which data concept is being addressed?
Hard353A data analyst is using pandas to clean a DataFrame. They need to replace missing values in the 'age' column with the median age. Which method should they use?
Hard354A data analyst is tasked with collecting data from a web API that returns JSON. The API requires an API key in the header. Which method should be used to authenticate?
Easy355A data analyst is cleaning a dataset and finds that 5% of values in the 'income' column are missing. The analyst decides to impute missing values using the mean of the non-missing values. Which potential issue should the analyst be most concerned about?
Hard356Which chart type is best for showing the sales pipeline from leads to closed deals, illustrating how many prospects drop off at each stage?
Easy357The exhibit shows a JSON schema for a dataset. Which statement correctly describes the data types represented?
Medium358An organization is integrating data from multiple sources into a data warehouse. They need to handle differences in data granularity (e.g., daily vs. hourly sales data). Which technique is most appropriate?
Medium359A data analyst creates a bar chart to compare average customer satisfaction scores across five departments. The chart shows very tall bars for three departments and very short bars for two departments, making differences hard to assess. What is the most likely cause and the best fix?
Hard360An organization is implementing a data lake to store raw data from various sources. Which THREE characteristics are typically associated with a data lake compared to a data warehouse?
Easy361In Tableau, you want to create a view showing the total sales per region, but also want to allow users to filter by year without losing the ability to see all regions. What feature should you use to compute the total sales that ignores the year filter?
Hard362A company needs to store data that is highly interconnected, such as social network relationships. Which two database types are best suited for this? (Select TWO.)
Medium363A dataset contains a variable 'Income' with many missing values. The analyst decides to impute missing values with the median income of the non-missing values. Which type of imputation is this?
Medium364A data analyst needs to extract the year from a column named 'order_date' in a SQL database. The database supports standard SQL functions. Which function should they use?
Medium365A business analyst needs to explain to a sales director that the reported revenue has a 95% confidence interval of ±2%. Which concept is being communicated?
Medium366A data analyst wants to generate a report showing employee names and their department names, but some employees are not assigned to any department. The analyst wants to include all employees. Which JOIN type should be used?
Medium367A data analyst needs to identify outliers in a dataset. Which of the following is a common method based on the interquartile range (IQR)?
Easy368A data analyst needs to count the number of distinct product categories in a table named 'products'. Which SQL function should be used in the SELECT clause?
Easy369Which THREE of the following are assumptions of linear regression? (Select THREE).
Hard370Which TWO of the following are examples of supervised learning algorithms?
Easy371A dashboard should be designed so that the most important metric is prominently displayed. This is an example of which design principle?
Easy372A company needs to visualize the trend of monthly sales revenue over the past two years. Which chart type is most appropriate?
Easy373A data analyst is examining the relationship between advertising spend (in dollars) and revenue (in dollars). The Pearson correlation coefficient r is calculated as +0.92. Which of the following interpretations is correct?
Medium374A data analyst wants to extract the year from a date column 'order_date' in a SQL database. Which function should be used?
Medium375A data analyst creates a heatmap to show website click-through rates by hour and day of week. The heatmap uses a green-to-red gradient, but users cannot distinguish between moderate values. What is the best fix?
Hard376Refer to the exhibit. What data quality issue is indicated?
Easy377A company needs to store raw, unprocessed data from IoT sensors for future machine learning experiments. The data is in various formats and schemas are not yet defined. Which storage solution is most appropriate?
Easy378A data governance team is defining roles and responsibilities for data management. Which TWO of the following are common data governance roles? (Select TWO).
Medium379In a dataset of customer orders, you need to count the number of distinct customers who have placed orders. Which SQL aggregate function should you use?
Easy380A data analyst needs to identify the most frequently occurring value in a dataset. Which measure of central tendency should they use?
Easy381Which TWO chart types are best suited for visualizing the distribution of a single continuous variable? (Select two.)
Medium382A data analyst is performing a chi-square test of independence on a contingency table of customer satisfaction (satisfied vs. dissatisfied) and product type (A, B, C). The test yields a p-value of 0.04 with α = 0.05. What is the correct conclusion?
Hard383A company wants to share a dataset with external partners via an API. Which API type is typically used for web services and uses XML or JSON for messaging?
Medium384A dashboard designer needs to ensure that color choices are accessible to users with color vision deficiencies. Which practice should be followed?
Easy385A company wants to segment its customers into distinct groups based on purchasing behavior. Which algorithm is best suited for this task?
Medium386A data analyst is designing a dashboard for executives to monitor company performance. Which THREE practices should the analyst follow to ensure effective storytelling with data? (Select three.)
Hard387A company runs an A/B test to compare a new website layout (treatment) against the current layout (control). The conversion rate for the control is 5% and for the treatment is 5.5%. The p-value is 0.06 at α=0.05. Which THREE of the following conclusions are valid?
Hard388A dataset contains a column 'birthdate' in 'YYYY-MM-DD' format. The analyst needs to calculate the average age of customers as of today. Which combination of functions is most appropriate?
Medium389A data analyst is working with a sales table that contains columns: sale_id, product_id, sale_date, and amount. They need to calculate a 7-day moving average of sales amount for each product, ordered by sale_date. Which window function syntax should they use?
Hard390A data analyst notices that two departments report different revenue totals for the same period. Which data governance issue is most likely?
Hard391Which TWO are best practices for data storytelling?
Medium392A retail company has a data warehouse that integrates sales data from multiple sources including online transactions, in-store POS, and third-party marketplaces. The data team recently updated the ETL pipeline to add a new data source: mobile app purchases. After the update, the daily sales report shows a 15% increase in total sales compared to the previous day, which is unexpected because the mobile app is new and only contributed 2% of sales in tests. The report is created by a SQL script that aggregates sales by date and runs every morning. The data team needs to identify the cause of the discrepancy. Which of the following should the team do first?
Easy393An analyst is presenting findings to stakeholders. Which TWO techniques effectively communicate uncertainty in data? (Choose TWO.)
Medium394Which of the following data types best describes a JSON file containing customer orders with varying fields per record?
Easy395A data analyst needs to present the correlation between advertising spend and website traffic. Which chart type is most appropriate?
Easy396A company wants to show the number of products sold across different categories: Electronics, Clothing, Home Goods, and Books. Which chart type is most appropriate?
Easy397A data analyst at a marketing firm is creating a weekly performance report for the marketing team. The report includes metrics like click-through rates, conversion rates, and cost per acquisition. The team prefers a quick overview of the week's performance to identify trends and make decisions in their Monday morning meeting. The meeting is only 30 minutes, and the team has limited time to review data. The analyst wants to provide a report that is concise and actionable. What format should the analyst use?
Easy398A data analyst is creating a dashboard for a sales team. Which TWO actions adhere to dashboard design best practices?
Medium399A data team is using web scraping to collect competitor pricing data. The target website has anti-scraping measures like CAPTCHAs and rate limiting. Which approach is most effective?
Hard400A data analyst creates a bubble chart showing country GDP (x-axis), life expectancy (y-axis), and population (bubble size). However, large bubbles overlap and obscure many data points. Which corrective action should the analyst take?
Hard401Which of the following best describes a data mart?
Easy402Which THREE elements should be included in a data insight report to ensure it is actionable? (Choose three.)
Medium403A dataset contains features with vastly different scales (e.g., age 0-100 and income 0-1,000,000). Which data transformation should be applied before using a K-nearest neighbors algorithm?
Medium404A data analyst is preparing a dataset for analysis and needs to ensure data quality. Which TWO of the following are dimensions of data quality?
Medium405A data analyst wants to test if the proportion of customers who prefer Product A over Product B is different from 50%. She surveys 200 customers and finds that 120 prefer Product A. Which statistical test should she use?
Medium406Which of the following is an example of semi-structured data?
Easy407A company uses a data warehouse for reporting. They need to extract data from multiple sources, load it into a staging area, and then transform it before moving to the warehouse. This process is known as:
Medium408Which THREE characteristics describe unstructured data? (Select three.)
Hard409Refer to the exhibit. A data analyst is creating a report that includes customer transaction data from 6 years ago. According to the policy, what should the analyst do?
Hard410Which of the following is a key performance indicator (KPI) tied to a strategic objective, as opposed to a metric?
Easy411A retail company wants to predict sales based on advertising spend and season. Which data modeling technique should the analyst use?
Medium412A healthcare organization maintains a database of patient records. The database has a table 'patients' with columns: patient_id (primary key), first_name, last_name, date_of_birth, gender, and last_visit_date. A data analyst is tasked with creating a report that lists all patients who have not visited in the last two years. The analyst writes a query: SELECT * FROM patients WHERE last_visit_date < DATEADD(year, -2, GETDATE()); However, the query returns zero rows, even though the analyst knows there are patients who have not visited for over two years. Upon inspection, the analyst discovers that the last_visit_date column contains NULL values for patients who have never visited. Which modification to the query should the analyst make to include patients with NULL last_visit_date?
Medium413A data team is preparing data for a clustering analysis. Which THREE of the following steps are commonly part of data cleaning?
Medium414Match each data analysis tool to its primary function.
Medium415A financial analyst wants to create a dashboard that shows the monthly profit and loss, highlighting how each component (revenue, cost of goods sold, operating expenses) contributes to the final net profit. Which chart type is most appropriate?
Medium416In Power BI, an analyst wants to create a measure that calculates the total sales for the current year up to the latest date in the data. Which DAX function should be used?
Hard417A data analyst needs to retrieve all unique job titles from an employees table. Which SQL keyword should be used in the SELECT clause?
Easy418A data analyst uses a Common Table Expression (CTE) to query hierarchical employee data (manager_id references employee_id). Which THREE statements about recursive CTEs are correct? (Select THREE).
Hard419A healthcare organization collects patient questionnaire data via paper forms at clinics. The forms are scanned and sent to a central office, where staff manually enter data into an electronic system. This process is slow and error-prone. The organization wants to reduce manual entry errors and speed up data availability. Which method should they adopt?
Easy420A data scientist is performing K-means clustering on customer data. She plots the within-cluster sum of squares (WCSS) for different values of k and observes an 'elbow' at k=4. What does this indicate?
Medium421Which of the following is a key difference between a Key Performance Indicator (KPI) and a metric?
Easy422An analyst has a dataset with monthly sales figures for the past five years. They want to highlight the cumulative effect of sales over time and show the total contribution of each month stacked on top of previous months. Which chart type is most suitable?
Hard423An e-commerce company wants to integrate product pricing data from competitor websites to adjust its own prices dynamically. They plan to scrape pricing pages every hour. However, the competitors' websites have anti-scraping measures such as IP blocking and CAPTCHAs. The company's legal team also advises caution regarding terms of service. Which data acquisition strategy is both effective and compliant?
Medium424Which TWO of the following are characteristics of a data lake?
Easy425Which TWO of the following are characteristics of structured data? (Choose TWO.)
Medium426A data analyst is evaluating a multiple regression model with three predictors. The R² value is 0.85. Which of the following is the best interpretation of R²?
Medium427Refer to the exhibit. Which data concept does this exhibit best represent?
Medium428A financial institution wants to analyze transaction networks to detect fraud rings. Which database type is best suited for this analysis?
Hard429A data analyst is troubleshooting a report that shows unusually high sales for a specific product. Upon investigation, the analyst finds that the product was returned by several customers, but the returns were recorded in a separate system and not reflected in the sales data. Which data integration concept was likely missing?
Hard430A business needs to store large volumes of raw data in its native format for future analytics. Which storage architecture is most appropriate?
Medium431A data analyst is using pandas in Python to merge two DataFrames: sales (columns: sale_id, product_id, amount) and products (columns: product_id, product_name). Which pandas function should they use to combine these DataFrames on the 'product_id' column?
Medium432You are a data analyst for an e-commerce company. Your team has built a dashboard to monitor daily sales performance across five regions: North, South, East, West, and Central. The dashboard includes a bar chart showing total sales per region, a line chart showing daily sales trend over the past 30 days, and a pie chart showing sales distribution by product category (Clothing, Electronics, Home, Books, Sports). Recently, stakeholders have complained that the pie chart is hard to interpret because the Sports category has very small sales and is barely visible. Also, the bar chart uses a rainbow color scheme that makes it difficult to compare bar heights because the colors are not ordered by magnitude. The line chart is fine. You need to redesign the dashboard to address these issues. Which combination of changes is most appropriate?
Hard433A market research firm collects survey responses where customers rate satisfaction on a scale of 'Very Unsatisfied', 'Unsatisfied', 'Neutral', 'Satisfied', 'Very Satisfied'. What type of data is being collected?
Easy434A database designer wants to improve query performance on a large table that is frequently filtered by multiple columns. Which TWO types of indexes could be beneficial? (Select TWO).
Medium435Which TWO of the following are dimensional modeling techniques commonly used in data warehouses?
Easy436A data scientist trains a regression model and observes high variance with low bias. Which technique is most appropriate to reduce variance?
Hard437A data analyst is communicating insights about a sales forecast to stakeholders. Which three of the following should the analyst include to build trust and clarity? (Select THREE.)
Hard438A data analyst frequently receives ad hoc requests for the same type of analysis. Which TWO approaches could reduce the number of ad hoc requests?
Medium439An executive dashboard must display high-level KPIs such as current revenue, profit margin, and customer count. Which visualization type is most appropriate for each KPI?
Medium440A data analyst is creating a self-service reporting environment. Which data governance practice ensures users see only data relevant to their department?
Hard441An analyst is creating a report in Power BI and needs to calculate year-to-date total sales compared to the same period last year. Which TWO DAX functions should be used? (Choose two.)
Medium442A data scientist is building a machine learning model to predict customer churn. The dataset includes both numerical features (age, income) and categorical features (gender, marital status). Which data concept describes the process of converting categorical features into numerical values that can be used by the algorithm?
Hard443An analyst needs to communicate a data insight about a sudden drop in website traffic. Which communication method should be used first?
Easy444A logistic regression model predicts customer churn (0=no churn, 1=churn). The model outputs probabilities. Which THREE of the following statements about logistic regression are correct?
Hard445A data analyst is performing data profiling on a customer table. Which metric would best help identify missing values in the 'phone' column?
Easy446A DBA wants to improve query performance on a large table that is frequently filtered on two columns: department_id and hire_date. The table has millions of rows. Which index strategy would be most effective?
Hard447A data analyst is performing a chi-square test for independence between two categorical variables. Which THREE of the following are necessary conditions for the test to be valid?
Hard448A retail company wants to analyze monthly sales data over the past three years to identify long-term trends. Which component of time series analysis is most relevant for this goal?
Easy449When the analyst runs the query, it fails. What is the most likely reason?
Medium450A company is planning an A/B test to compare two website designs. Which THREE of the following must be determined before the test begins to ensure valid results? (Select three.)
Hard451Drag and drop the steps for the ETL (Extract, Transform, Load) process in the correct order.
Medium452A marketing analyst wants to segment customers based on their purchase history, including total spent, number of transactions, and average order value. The analyst runs k-means clustering with k=5 on the raw data but notices that the cluster assignments change significantly every time the algorithm is executed. What should the analyst do first to obtain consistent and meaningful clusters?
Easy453Refer to the exhibit. Which clause is used to aggregate the data by department?
Easy454An analyst wants to visualize the relationship between advertising spend (x-axis) and revenue (y-axis) for 100 different products. Each product is in one of three categories. Which chart type best displays this data?
Medium455A data analyst creates a weekly KPI dashboard for executives. The analyst notes that the data is updated as of the previous day. Which report quality element should be included?
Medium456When designing a report for executive leadership, which aspect is most important?
Easy457You are a data analyst at a logistics company. The operations manager wants to reduce delivery delays. You have historical data including order date, delivery date, distance, weather conditions, and driver ID. Initial analysis shows that the average delivery time has increased over the past six months. You suspect that weather is a contributing factor, but you need to confirm. The company also wants to build a model to predict delivery times to better manage customer expectations. The data contains missing values for weather conditions in about 10% of records, and some driver IDs are incorrect. You have limited time and resources. What should you do first?
Easy458Which THREE actions improve the accessibility of data visualizations for users with visual impairments? (Select exactly three.)
Hard459An analyst creates a stacked bar chart showing quarterly sales by product category. The chart becomes hard to read because some categories have very small contributions. Which redesign is most effective?
Hard460A data analyst is cleaning a dataset and finds that the 'age' column has several missing values. Which method of handling missing values is least likely to introduce bias if the missingness is completely at random?
Medium461A data analyst is comparing the means of two independent groups using a t-test. The sample sizes are small and the data is not normally distributed. Which condition is violated for a valid t-test?
Hard462A data analyst finds that the "Age" column contains values like "N/A", "unknown", and negative numbers. Which data quality dimension is primarily affected?
Medium463A data analyst needs to sample records from a large dataset for a quick analysis. Which TWO sampling methods are examples of probability sampling?
Easy464An IT operations team monitors 200 servers. Each server reports CPU utilization (0-100%) every five minutes for the past year. The team wants to visualize the data to identify servers that are consistently over 80% utilization and detect any unusual spikes. They have a large dataset with 100,000+ records per server. The current visualization is a single scatter plot with CPU utilization on the y-axis, time on the x-axis, and each server as a different colored point. The chart is extremely cluttered, with points overlapping and colors indistinguishable. What should the team do to improve the visualization?
Hard465A data analyst needs to summarize customer satisfaction scores. The data contains a few extremely low scores that skew the distribution. Which measure of central tendency is most appropriate?
Easy466Which of the following is an example of qualitative data?
Easy467An analyst wants to identify outliers in a dataset using the IQR method. Which values are typically considered outliers?
Easy468In pandas, you have a DataFrame 'df' with columns 'product' and 'sales'. You want to calculate the total sales per product. Which method should you use?
Easy469A data analyst is performing a join between two tables: 'employees' and 'departments'. The 'employees' table has a foreign key 'dept_id' referencing the 'departments' table. Which two join types would include all rows from the 'employees' table, regardless of whether there is a matching department? (Select TWO)
Medium470A data analyst is performing data cleaning on a dataset and identifies several outliers in the 'age' column. Which TWO methods are appropriate for handling these outliers? (Select two.)
Medium471Match each database concept to its definition.
Medium472A data analyst is building a model to predict customer churn. The dataset has 10,000 records with 500 churned customers. The model predicts churn with 95% accuracy, but only identifies 10% of actual churners. Which metric best highlights this issue?
Hard473In an A/B test, the null hypothesis states that there is no difference between the control and treatment groups. After running the test, the p-value is 0.04. Assuming α = 0.05, what is the correct conclusion?
Easy474A dataset contains a column 'Income' with values in different scales (some in thousands, some in hundreds). What is the best way to standardize this column for use in a machine learning model?
Easy475In SQL, you want to retrieve all products whose names start with 'Pro'. Which WHERE clause should you use?
Easy476A data analyst is documenting a report for external stakeholders. Which THREE elements should be included to ensure report quality and transparency?
Medium477After building a binary classification model, the data analyst obtains the following confusion matrix: True Positives=80, True Negatives=100, False Positives=20, False Negatives=30. What is the F1 score?
Hard478An analyst is creating a report for both technical and executive audiences. Which two strategies are effective? (Choose TWO.)
Medium479A dashboard shows sales by region using a map with color intensity. Users complain that two regions with very different sales appear nearly the same color. What is the most likely cause?
Medium480A university database stores student information in a normalized schema. The 'students' table has a primary key 'student_id'. The 'enrollments' table has a foreign key 'student_id' referencing 'students'. Which two of the following are true about primary and foreign keys? (Select TWO)
Medium481A data analyst is creating a report that includes customer names and addresses. To comply with privacy regulations, which TWO actions should the analyst take?
Medium482A data analyst wants to combine first_name and last_name columns into a single full_name column in a SQL query. Which string function should be used?
Easy483Which TWO actions will improve the readability of a bar chart showing quarterly sales across five regions?
Medium484A data analyst is preparing a presentation on customer churn. The audience consists of both technical and non-technical stakeholders. Which visualization approach is most effective?
Hard485Refer to the exhibit. An Avro schema is defined as shown. Which data design concept does this represent?
Easy486A retail company has collected data on monthly advertising spend (in thousands of dollars) and corresponding sales (in thousands of dollars) over the past 12 months. The analyst creates a scatter plot to visualize the relationship between advertising spend and sales. The plot shows a cluster of points with a positive trend, but there is one extreme outlier where spend was $100,000 but sales were only $20,000. Upon investigation, the analyst discovers that the outlier is due to a data entry error: the sales figure should have been $200,000. The analyst wants to present the overall trend accurately in a meeting. Which course of action should the analyst take first?
Easy487A data analyst is preparing to build a predictive model. Which TWO steps are essential to ensure model validity? (Choose two.)
Easy488You have a hierarchical table 'Employees' with columns emp_id, emp_name, manager_id (referencing emp_id). You need to generate a full reporting chain from a given employee up to the CEO. Which SQL construct is most appropriate?
Hard489A data analyst needs to combine data from two tables: one containing customer information and another containing order details. The analyst wants to include all customers, even those who have not placed any orders. Which type of join should be used?
Medium490A data engineer is comparing data warehouses and data lakes. Which statement accurately describes a data warehouse?
Medium491A data analyst is preparing a dataset for analysis and needs to address data quality issues. Which TWO of the following are common data cleaning tasks?
Medium492Refer to the exhibit. An analyst runs a query to count orders in June 2023 and gets 12,345. However, a dashboard shows 12,298 for the same month. What is the most likely cause?
Medium493Match each ETL process step to its description.
Medium494In a Power BI report, a user wants to create a measure that calculates total sales for the current year up to today. Which DAX function should they use?
Medium495A marketing team wants to segment customers into distinct groups based on purchasing behavior. The data includes numeric features such as frequency, monetary value, and recency. Which unsupervised learning algorithm should be used?
Easy496An analyst is performing EDA and wants to measure the strength and direction of linear relationship between two continuous variables. Which statistical measure should they compute?
Medium497During data acquisition, a data engineer uses a tool to extract data from a source system incrementally based on a timestamp column. Which method is being used?
Medium498A data analyst reports being unable to run the query shown in the exhibit. The data governance team reviews the access control policy. Which of the following is the most likely explanation for the denied access?
Medium499Which TWO are examples of leading indicators in a business context? (Select two.)
Medium500A data analyst is using pandas to read a CSV file named 'sales.csv'. Which line of code correctly reads the file into a DataFrame?
Medium501A data engineer is designing a system to handle high-velocity clickstream data from a website. The system must allow low-latency writes and support key-value lookups. Which type of database is most appropriate?
Hard502Which of the following data types is characterized by a flexible schema and is commonly represented using JSON or XML?
Easy503A company is merging two databases from different departments. In Database A, customer IDs are integers. In Database B, customer IDs are alphanumeric strings. To merge, the data analyst must reconcile these differences. Which step should be taken first?
Hard504Which THREE data sources are suitable for web scraping? (Select three.)
Easy505A data scientist is cleaning a dataset and notices missing values in several columns. Which THREE techniques are appropriate for handling missing data? (Select THREE.)
Hard506A mid-sized e-commerce company stores customer data in a relational database. The database has a table named 'Customers' with columns: CustomerID (primary key), FirstName, LastName, Email, Phone, Address, City, State, ZipCode, and SignUpDate. The company is migrating to a new CRM system that requires a denormalized structure for performance reasons. The new system expects a single table 'CustomerDetails' with columns: CustomerID, FullName (concatenation of first and last name), ContactInfo (JSON object containing email, phone, and address), SignUpDate, and Region (derived from state). The data analyst must design an ETL process to transform the data. During a test run, the analyst notices that some records have missing Phone or Address values. Which of the following is the best approach to handle missing data in the ContactInfo JSON object?
Hard507A data analyst is cleaning a customer dataset. Which two actions are appropriate for handling duplicate records? (Choose TWO)
Medium508A healthcare analytics team is responsible for producing a monthly dashboard for hospital administrators. The dashboard includes key metrics such as patient admission rates, average length of stay, readmission rates, and bed occupancy. For the current month, the data shows a significant increase in average length of stay. The data analyst suspects that this increase is due to a new chronic disease management program that was implemented at the beginning of the month. However, the analyst also notices that the data for the previous month had an error: some discharge dates were incorrectly recorded, causing the average length of stay to be artificially low. The analyst needs to communicate the insights to the administrators, who are concerned about the increase. Which of the following is the best course of action?
Medium509Refer to the exhibit. The data shown is an example of which data concept?
Easy510A data pipeline log shows the above error. Which data transformation should be applied during acquisition?
Hard511An e-commerce company uses a star schema for its data warehouse. The fact table 'sales_fact' contains foreign keys to dimension tables: customer_dim, product_dim, time_dim, and store_dim. A business user wants to know the total sales for each product category in the last month. Which join operation is required to retrieve this data?
Medium512A data analyst is preparing features for a machine learning model that uses distance-based algorithms (e.g., K-means, KNN). The dataset contains numerical features with different scales: age (0-100), income (20,000-200,000), and credit score (300-850). Which data transformation technique is most appropriate to ensure all features contribute equally to the distance calculations?
Medium513A sensor records temperature readings in Celsius and a separate sensor records wind speed in meters per second. A data scientist wants to combine these datasets for analysis. Which statement accurately compares these data types?
Hard514A healthcare data analyst is presenting findings on patient readmission rates to a group of hospital administrators. The analysis reveals a 15% increase in readmissions over the past quarter for patients aged 65+ from a specific zip code. However, the administrators are skeptical because previous quarterly reports showed no such trend, and they suspect data quality issues. The analyst must communicate this insight effectively while maintaining credibility. Which of the following approaches should the analyst take?
Hard515A data analyst is preparing a report on regional sales performance. The report will be viewed by regional managers who should only see their own region's data. Which TWO data governance measures are most relevant?
Hard516A data analyst is profiling a dataset and finds that the 'email' column contains some NULL values. Which SQL query can be used to count how many rows have a NULL email?
Medium517A data analyst runs the query: SELECT AVG(salary) FROM employees GROUP BY department HAVING AVG(salary) > 60000. What is the purpose of the HAVING clause?
Medium518Which TWO of the following are best practices for designing an accessible data visualization? (Choose 2.)
Medium519A data analyst is cleaning text data in a SQL database. Which THREE string functions are commonly used to standardize and clean text? (Choose three.)
Medium520A financial analyst is integrating data from multiple stock exchanges. One exchange provides trade timestamps in UTC, another in Eastern Time. The analyst needs accurate time synchronization for time-series analysis. What is the best approach?
Hard521A company is designing a data pipeline to process streaming data from social media feeds. Which THREE of the following are characteristics of streaming data? (Select THREE).
Hard522A data analyst is performing EDA on a dataset with numerical features. Which methods are appropriate for identifying outliers? (Select TWO).
Hard523A heat map of store sales by region shows very low correlation between advertising spend and revenue, but a scatter plot of the same data shows a strong positive relationship. What is the most likely cause?
Hard524A data analyst is testing whether the average sales amount differs between two regions. Which statistical test is most appropriate?
Medium525A data scientist builds a simple linear regression model to predict house prices based on square footage. The model yields an R-squared value of 0.85. Which statement accurately interprets this result?
Medium526A data analyst is performing a chi-square test of independence on a contingency table of customer satisfaction (satisfied, neutral, dissatisfied) by region (North, South, East, West). Which THREE of the following are necessary assumptions for the test?
Hard527A dataset contains customer records with a column for 'Phone Number' that should be unique. However, the analyst finds several duplicate phone numbers. Which data quality dimension is primarily affected?
Easy528A data analyst runs a query to count the number of customers in each city. The query uses COUNT(*) and GROUP BY city. However, the result includes NULL for some cities. What will COUNT(*) return for a group where the city is NULL?
Medium529A marketing team runs an A/B test on email subject lines. The p-value is 0.03 with α = 0.05. Which of the following is the correct interpretation?
Medium530Refer to the exhibit. An analyst sees this log during data acquisition. What action should be taken first?
Hard531Which TWO of the following are examples of data governance best practices?
Hard532A market researcher conducts a survey with questions like "What is your favorite brand?" and "How many units do you purchase per year?" Which data types correspond?
Easy533You are a data analyst at a retail company. The marketing team has asked you to analyze the effectiveness of a recent email campaign. You have data on email open rates, click-through rates, and conversion rates. The campaign targeted 50,000 customers; 20,000 opened the email, 5,000 clicked a link, and 500 made a purchase. The marketing director wants to know the campaign's overall performance and whether the email content was engaging. You prepare a dashboard but notice that the click-through rate (CTR) is 25% and the conversion rate is 10%, which seem high. Upon reviewing the data, you discover that the click-through rate was calculated as (clicks / opens) * 100, and the conversion rate as (purchases / clicks) * 100. The director expects the conversion rate to be calculated as (purchases / opens) * 100. Which action should you take to ensure accurate communication of insights?
Easy534A retail company's data analytics team needs to acquire point-of-sale (POS) transaction data from 200 stores daily. Each store sends a CSV file via email at the end of the day. The files often arrive late, have inconsistent column names (e.g., "StoreID", "Store_ID", "store_id"), and occasionally contain corrupted rows. The team manually processes these files, leading to frequent errors and delays. The company wants to automate the acquisition process to ensure data is available by 9 AM the next business day with high quality. Which approach best addresses these issues?
Easy535A data analyst needs to display the distribution of customer ages in a dataset containing 10,000 records. Which TWO chart types are appropriate? (Choose two.)
Easy536An organization is acquiring data from an external vendor. The vendor provides a flat file with inconsistent delimiters and missing values. Which step should be performed first in data acquisition?
Hard537In logistic regression, the output is a probability between 0 and 1. If the predicted probability for a customer churning is 0.7 and the decision threshold is 0.5, what is the predicted class?
Hard538Drag and drop the steps to implement a data classification policy in the correct order.
Medium539A data analyst needs to communicate a forecast with uncertainty. Which visualization is best?
Medium540A data analyst is validating a dataset acquired from an external source. Which TWO actions are appropriate for data quality assessment?
Easy541A marketing company is building a customer segmentation model. The data team has access to two sources: a CRM database with customer demographics and purchase history, and a third-party data provider that offers social media activity scores. The CRM data is updated daily, while the third-party data is refreshed weekly on Sundays. The analyst needs to create a unified dataset for the model training scheduled for Wednesday morning. The analyst runs a SQL query to join the two tables on CustomerID, but the resulting dataset has far fewer rows than expected. Upon investigation, the analyst finds that many customers in the CRM do not have matching records in the third-party data. Additionally, some customers in the third-party data have multiple entries due to unresolved duplicates. The analyst must produce the most complete dataset possible while maintaining data quality. Which course of action should the analyst take?
Easy542A company wants to ensure that data visualizations are accessible to colorblind users. Which of the following is a best practice?
Easy543Refer to the exhibit. A data analyst attempts to visualize the dataset but receives a permission error. The analyst's username is 'analyst2'. What is the most likely cause?
Medium544Which TWO roles are primarily responsible for defining and enforcing data governance policies within an organization?
Medium545Which TWO of the following are true about Pearson correlation coefficient (r)?
Medium546What is the primary purpose of the HAVING clause in the query shown?
Medium547A company stores customer data in a relational database with tables for orders, products, and customers. Which type of data best describes this?
Easy548A data analyst is creating a dashboard to monitor server CPU utilization over the past 24 hours. Which chart type is most appropriate for showing the trend of CPU usage over time?
Easy549A data analyst is analyzing customer purchase amounts. The dataset contains several extreme high values due to luxury purchases. Which measure of central tendency is most robust to these outliers?
Medium550A financial analyst wants to compare the mean annual returns of three different investment strategies. Which statistical test is most appropriate?
Medium551Which TWO of the following are considered internal data sources within an organization?
Easy552A data analyst is preparing data for a k-nearest neighbors algorithm. The features include age (0-100) and income (0-200,000). Which technique should be applied to ensure the distance metric is not dominated by income?
Medium553A data analyst is creating a dashboard for executives to show monthly sales trends over the past year. Which chart type is most appropriate?
Easy554A data analyst is preparing a presentation for a mixed audience of executives and technical staff. Which two of the following practices would be most effective? (Select TWO.)
Easy555A dashboard designer wants to maximize the data-ink ratio. Which action should they take?
Medium556A financial analyst is building a model to predict stock price movements. The data is time series with daily prices. The analyst wants to use a regression model but notices that the residuals are autocorrelated. What adjustment should be made?
Hard557A company is designing a database for an e-commerce application that requires high transaction throughput and must guarantee that each transaction is processed atomically. Which property of ACID ensures that a transaction is either fully completed or not executed at all?
Easy558A financial application requires fast query performance for aggregations on large historical datasets. The schema has many lookup tables. Which schema design is most efficient for this workload?
Medium559A data analyst is working with a dataset that includes a column 'income' with values ranging from 20,000 to 150,000. To standardize this variable for a linear regression that assumes normally distributed residuals, which method should be used?
Medium560A data analyst needs to visualize sales per capita across U.S. states. States with small populations but high sales (e.g., Delaware) appear too prominent on a choropleth map. Which technique best addresses this issue?
Hard561A retail company processes daily transactions. The current system transforms data before loading it into the data warehouse. The volume is growing rapidly, and they want to load raw data first to reduce processing time. Which approach should they adopt?
Easy562Which TWO actions are appropriate when creating a data visualization for a diverse audience with varying levels of data literacy? (Choose two.)
Easy563During ETL, a data analyst discovers that a date column contains values like '01/02/2023' and '2023-01-02'. Which of the following is the best practice to ensure consistent date format before analysis?
Easy564Which data cleaning method involves replacing a missing value with the average of the available values in that column?
Easy565A data analyst needs to collect customer sentiment data from social media platforms. Which data acquisition method is most appropriate?
Easy566A data analyst is building a linear regression model to predict sales based on advertising spend across TV, radio, and newspaper channels. Which TWO diagnostics should the analyst perform to validate the model assumptions?
Easy567A company has a dataset with 100 features. The data analyst wants to reduce dimensionality while preserving as much variance as possible. Which technique should be used?
Medium568A data analyst calculates a correlation coefficient of -0.85 between temperature and heating costs. What does this indicate?
Easy569A data analyst is validating referential integrity between orders and customers tables. Which TWO of the following checks should the analyst perform?
Medium570A sales analyst is designing a report for the sales team that includes the number of new leads, conversion rate, and total revenue. The team wants to identify which metrics are Key Performance Indicators (KPIs) tied to the strategic goal of increasing revenue. Which TWO of the following should be classified as KPIs?
Medium571Refer to the exhibit. An analyst runs the following query: SELECT product_id, AVG(quantity) FROM sales GROUP BY product_id HAVING AVG(quantity) > 8; Which product_id(s) will be returned?
Medium572Which TWO are examples of primary data? (Select two.)
Easy573Refer to the exhibit. A data analyst is trying to understand access permissions for the company data folder. Which statement accurately describes the effective permissions?
Medium574A data analyst is performing a multiple linear regression with three predictors. The model output shows an R-squared of 0.85 and an adjusted R-squared of 0.80. Which of the following is the best interpretation of the difference between these two values?
Hard575An analyst is creating a dashboard in Power BI to track sales performance. They want to ensure that when a user selects a specific product category on a slicer, all other visuals on the page filter to show data only for that category. Which TWO actions should the analyst take?
Medium576Which TWO are common methods for acquiring internal data? (Choose two.)
Easy577A company is ingesting data from multiple sources into a cloud data warehouse. They decide to load the data raw and then perform transformations within the warehouse. Which approach does this describe?
Medium578A marketing team uses K-means clustering to segment customers based on purchase history. To determine the optimal number of clusters, they plot the within-cluster sum of squares (WCSS) against k and look for an elbow. What is the purpose of this method?
Medium579During an ETL process, a data quality check fails due to duplicate customer IDs. Which data quality dimension is violated?
Hard580A data team is integrating customer data from three sources. After joining, they find that the count of unique customers is lower than expected. What is the most likely cause?
Hard581A data analyst needs to visualize the distribution of salaries across departments and also compare the median and identify outliers. Which chart type is most suitable?
Medium582A data analyst needs to perform a stratified random sample of a customer database. Which TWO steps are essential for this sampling method? (Select two.)
Medium583An analyst presents a report to stakeholders who are not data-savvy. The report includes a box plot showing the distribution of customer satisfaction scores. One stakeholder asks, 'What do the whiskers mean?' Which communication strategy should the analyst use?
Hard584After training a decision tree, the tree has depth 20 and 100% accuracy on training data but only 60% on test data. Which hyperparameter adjustment is most likely to improve generalization?
Hard585A dashboard designer wants to ensure the most important KPI is prominently displayed at the top left. Which design principle is being applied?
Medium586A data analyst is tasked with combining customer data from a CRM system and a billing system. The CRM uses a GUID for customer ID, while billing uses an integer. Which approach should the analyst use to ensure a reliable merge?
Medium587A company is migrating its data pipeline from on-premises to the cloud. The current ETL process transforms data before loading into a data warehouse. The new architecture will use ELT instead. Which THREE of the following are advantages of ELT over traditional ETL? (Select 3)
Hard588Which chart type is best for showing the distribution of a continuous variable, such as customer ages?
Easy589A data analyst needs to create a new column 'full_name' by concatenating 'first_name' and 'last_name' with a space. Which SQL function should be used in the SELECT clause?
Medium590A marketing analyst wants to visualize the conversion funnel from website visitors to paying customers. Which TWO chart types are suitable for showing this pipeline? (Choose two.)
Medium591A data analyst is conducting exploratory data analysis (EDA) on a dataset. Which TWO tasks are typically performed during EDA? (Select two.)
Medium592An analyst wants to show the distribution of test scores for 500 students. Which visualization type is best for understanding the shape of the distribution?
Easy593An analyst wants to compare the mean sales revenue across three different store regions. The data is normally distributed and variances are equal. Which statistical test is most appropriate?
Medium594A researcher is designing an A/B test to compare two website layouts. Which TWO elements are essential for determining the required sample size?
Medium595Refer to the exhibit. A data analyst wants to grant read access to an entire cloud storage bucket named 'data-lake'. Which of the following best describes what this policy does?
Easy596A data analyst is building a report that includes customer names and addresses. To comply with GDPR, what must the analyst do before publishing the report?
Medium597A data analyst needs to ensure that a customer's address is stored in a consistent format across multiple databases. Which data quality dimension is the analyst primarily concerned with?
Easy598A data quality assessment reveals that a column named 'email' contains values like 'user@example' (missing domain extension). Which data profiling technique would best identify such pattern violations?
Medium599A data analyst is writing a query to rank products by total sales within each category, showing dense rank and avoiding gaps. Which window function should be used?
Hard600A data analyst is cleaning a dataset and finds that some records have duplicate entries based on customer ID. Which data quality dimension is most directly affected by these duplicates?
Hard601You are a data analyst for a logistics company. The company has a fleet of delivery trucks and tracks performance metrics including delivery time, fuel consumption, and distance traveled. Management wants a dashboard to monitor driver efficiency and identify underperforming drivers. You have access to a dataset with columns: DriverID, Date, RouteID, Distance (miles), FuelUsed (gallons), DeliveryTime (minutes). The dataset contains 10,000 records from the past year. You need to create a visualization that allows management to quickly compare the average fuel efficiency (miles per gallon) of drivers and also see how consistent each driver's efficiency is. Which of the following approaches is the best course of action?
Hard602A data visualization specialist needs to display the relationship between advertising spend and revenue for 50 product categories over 12 months. The data has many overlapping points. Which chart type best reveals the correlation and density?
Hard603A data analyst needs to combine sales data from multiple regional databases with different schemas. Which process is best?
Medium604A healthcare company's data analyst is tasked with presenting patient readmission rates to a group of doctors and nurses. The data shows that readmission rates are higher among patients with certain chronic conditions. The audience has limited data literacy, but they are familiar with clinical terms. The analyst wants to communicate the insights effectively and encourage discussion on preventive measures. The presentation will last 15 minutes, and the audience expects actionable insights. What should the analyst do?
Medium605A finance department wants to compare actual expenses against budgeted amounts for each of 10 departments over the past 12 months. They need to show the variance (over/under budget) as well as the trend of expenses over time. The data includes monthly actual and budget figures for each department. The audience is the CFO who needs a quick overview. Which visualization approach should be used?
Medium606A data analyst is building a supervised learning model to predict customer churn. The target variable is binary (churn = yes/no). Which TWO modeling techniques are appropriate for this task? (Select two.)
Medium607A company wants to collect real-time clickstream data from its website. Which acquisition method is most suitable?
Medium608In a customer database, each row represents a customer with columns: CustomerID, Name, Address, Phone. What does the column "Name" represent?
Medium609Refer to the exhibit. A data pipeline is failing to parse this log entry. What is the most likely cause of the error?
Easy610A data governance team is establishing policies for data quality. Which THREE of the following are common dimensions of data quality? (Select 3)
Medium611A financial services company is migrating its customer data from a legacy on-premises relational database to a cloud-based data warehouse. The legacy database uses a denormalized schema with a single table 'customer_master' that contains all customer attributes, including repeated groups for multiple accounts per customer (account1_type, account1_balance, account2_type, account2_balance, etc.). The data warehouse team wants to implement a normalized star schema with separate dimension and fact tables. During the ETL process, the team encounters an error: 'Data truncation: string data right truncation' when loading account_type values into the dim_account table. The account_type column in dim_account is defined as VARCHAR(10), but the source data contains account types like 'SavingsPlus' (11 characters) and 'CheckingPremium' (15 characters). The team must resolve this issue without losing data. Which course of action should the team take?
Hard612A data analyst is building a narrative around a quarterly sales decline. The story should follow a narrative arc. Which THREE elements should be included in the story?
Hard613A data analyst needs to compare sales data from the company's internal CRM with public demographic data from a government census. Which data concept best describes this scenario?
Medium614Refer to the exhibit. The data shows sales by product category for two years. Which product category had the highest percentage increase from 2023 to 2024?
Easy615An analyst needs to show the part-to-whole relationship of market share among four competitors. Which chart type is most appropriate, considering best practices?
Medium616A data analyst wants to ensure a sample proportionally represents different regions in a population. Which sampling method should be used?
Medium617In time series decomposition, a pattern that repeats at regular intervals (e.g., weekly, yearly) is called:
Hard618A data analyst is cleaning a dataset and finds that some cells in the 'email' column contain leading spaces. Which string function should be used to remove these spaces?
Medium619A data analyst creates a bar chart showing monthly sales for the current year. The CEO asks to see the same data but grouped by region. Which chart type is most appropriate for this new requirement?
Easy620An analyst is using SQL to analyze employee data. Which THREE of the following are valid uses of the WHERE clause? (Select three.)
Hard621In Power BI, a developer needs to create a measure that calculates total sales for the same period last year. Which DAX function should be used?
Hard622A data analyst is creating a dashboard in Tableau to show monthly sales trends. The data source includes daily sales figures. The analyst needs to calculate the cumulative sales for each month and compare it to the same period last year. Which Tableau feature should be used for the year-over-year comparison?
Hard623A data analyst needs to extract data from an API that returns JSON. The analyst wants to convert the JSON output into a tabular format for analysis. Which function in a scripting language is commonly used for this purpose?
Easy624A scatter plot of advertising spend vs. revenue shows no clear correlation, but the analyst suspects a relationship exists. Which addition to the plot could help reveal a hidden trend?
Medium625A data analyst wants to visualize the monthly sales trend for the past year. Which chart type is most appropriate?
Easy626A database administrator wants to ensure that every value in a column matches values in a primary key column of another table. Which constraint enforces this rule?
Medium627An analyst is reviewing a table that stores customer orders. The table contains columns: OrderID, CustomerName, Product1, Product1Qty, Product2, Product2Qty. This design violates which normal form?
Hard628Which TWO are examples of internal data sources? (Select exactly 2)
Easy629A simple linear regression model predicts sales (y) from advertising spend (x). The equation is y = 2.5x + 10, and R² = 0.81. Which interpretation is correct?
Medium630In a time series analysis, a retail analyst observes consistent peaks in sales every December and troughs every February. This pattern repeats annually. Which component of time series does this represent?
Medium631Refer to the exhibit. A data analyst runs this query to identify high-value customers. However, the result does not include customers with exactly 5 orders. Which data concept does the HAVING clause illustrate?
Hard632A data analyst is preparing a presentation to share findings with non-technical stakeholders. Which TWO practices should the analyst follow to effectively communicate data insights? (Choose two.)
Easy633A dataset contains outliers in a feature that will be used for linear regression. Which two outlier treatment methods are appropriate? (Choose TWO)
Medium634Which TWO are best practices for designing effective dashboards? (Select exactly two.)
Medium635Refer to the exhibit. If the date column is stored as a string in 'MM/DD/YYYY' format, what will be the result?
Medium636A data scientist is tuning a decision tree model to prevent overfitting. The model currently has a high variance. Which hyperparameter adjustment is most effective?
Hard637A marketing analyst wants to segment customers based on purchasing behavior and demographics. The dataset includes continuous variables (spending amount, frequency) and categorical variables (region, gender). The analyst decides to use k-means clustering. What should the analyst do to prepare the data?
Hard638A data analyst is reviewing the quality of a sales report before publishing. Which THREE elements should the analyst include to ensure report quality?
Hard639A data analyst wants to compare the sales performance of four different stores over the same time period. Which chart type is most suitable?
Easy640A data analyst wants to predict customer churn based on categorical features like region and plan type, and continuous features like usage and tenure. Which regression type should be used?
Easy641During data exploration, an analyst notices that the target variable has a heavily right-skewed distribution. Which data transformation would be most appropriate to make the distribution more symmetric?
Easy642A company’s marketing team wants to segment customers based on purchase history, demographics, and website behavior. The data includes both numeric and categorical variables. Which clustering algorithm is best suited for handling mixed data types?
Medium643A data analyst needs to merge two customer tables from different sources. One table uses 'CUST_ID' as the primary key, the other uses 'CustomerID'. To ensure accurate merging, the analyst should first:
Easy644An analyst creates a dashboard with multiple visualizations. Which feature allows users to change the data displayed across all charts simultaneously?
Easy645A sales manager receives a daily report at 8 AM via email showing yesterday's sales by region. This is an example of which report type?
Medium646Refer to the exhibit. An analyst runs this query before acquiring data from a PostgreSQL database. What is the primary purpose of this query?
Easy647A data analyst is creating a report to compare the performance of sales regions across multiple years. The report will be used by regional managers to identify trends. Which visualization approach best supports this?
Hard648A data analyst is working with a dataset containing house prices. After building a multiple linear regression model, the analyst observes that the model performs well on training data but poorly on validation data. Which technique is most appropriate to address this issue?
Hard649A data analyst is tasked with gathering data from a legacy system that only exports CSV files. The files contain headers but no data types. Which tool would best facilitate initial data exploration?
Easy650A data team must implement a data retention policy to reduce storage costs while meeting legal requirements. Which TWO actions best achieve this?
Medium651During EDA, an analyst calculates the Z-score for each data point in a dataset. A data point with a Z-score of 3.5 is identified. What does this indicate?
Medium652A data analyst is preparing a logistic regression model to predict customer churn. After examining the exhibit, which data quality issue should the analyst address first?
Hard653A dataset contains a feature 'Age' with values ranging from 18 to 95. To prepare data for a k-nearest neighbors algorithm, which transformation should be applied to 'Age'?
Medium654A data analyst is reviewing a data lake access policy that controls access to a data lake. The analyst wants to communicate that the current policy restricts data downloads to a specific IP range. Which of the following best describes the policy's effect?
Hard655Drag and drop the steps to perform a data audit in the correct order.
Medium656Which TWO of the following are leading indicators that can help predict future performance?
Medium657A data analyst wants to compare the average revenue per customer between two marketing campaigns (A and B). The analyst is unsure if the data follows a normal distribution. Which statistical test is most appropriate for comparing the means of the two groups?
Medium658A retail company is merging customer data from three separate systems: an e-commerce platform, a point-of-sale (POS) system, and a loyalty program. The e-commerce platform stores customer names in "FirstName LastName" format, the POS system stores names as "LastName, FirstName", and the loyalty program stores names in separate "first_name" and "last_name" fields. The data analyst needs to create a unified customer master table. After initial merging, there are 20% more records than expected, including duplicates with slight name variations (e.g., "John Smith" vs "John A. Smith"). To ensure accurate consolidation, which data concept should the analyst prioritize applying first?
Easy659A report uses red and green colors to indicate performance; a stakeholder who is colorblind complains. What is the BEST remedy?
Medium660A data analyst has a time series of monthly sales data. They observe that sales are consistently higher every December and lower every January. Which component of time series does this pattern represent?
Hard661A data analyst is creating a dashboard in Looker Studio for an e-commerce company. They want to display the average order value by product category, and also allow users to filter by date range. Which combination of elements should be used?
Medium662A data analyst in a healthcare organization needs to visualize patient wait times across different departments. The data includes department names (categorical), wait times in minutes (continuous), and time of day. Which THREE chart types could be effectively used to explore this data?
Hard663Given the linear regression output, which independent variable has the strongest effect on price, based on standardized coefficients?
Hard664A data analyst is performing data profiling on a customer table. Which TWO metrics are commonly used to assess the completeness of a column? (Select TWO.)
Medium665Which TWO chart types are best suited to show the proportion of total sales contributed by each product category? (Select exactly two.)
Medium666Refer to the exhibit. What is the best course of action for the data analyst?
Hard667A company is building a data pipeline to ingest sensor data from IoT devices. The data arrives continuously in small batches and must be processed in real-time for monitoring. Which type of data source best describes this scenario?
Medium668A data engineer is designing a data pipeline to ingest streaming data from IoT sensors. The sensors send data every second, and the pipeline must handle bursts of up to 10,000 messages per second. Which approach is most appropriate for capturing this data before processing?
Hard669Which THREE of the following are valid methods for handling missing data?
Hard670When presenting data insights, which three practices help ensure clarity? (Choose THREE.)
Hard671A data analyst is asked to create a visualization showing the trend of monthly revenue over the last five years. Which chart type is most suitable?
Easy672A data analyst is importing a CSV file that contains a mixture of numeric and text fields. What is the most common issue when importing?
Easy673An analyst is conducting an A/B test to compare two website designs. The null hypothesis is that there is no difference in conversion rates. The p-value obtained is 0.03, and the significance threshold is 0.05. What should the analyst conclude?
Medium674An organization needs to store raw data from IoT sensors in its native format for future analysis. Which storage solution is best suited for this purpose?
Easy675A data analyst is building a Power BI report to track KPIs for a retail chain. Which TWO of the following are considered leading indicators? (Choose two.)
Medium676Which of the following is an example of unstructured data?
Easy677A data analyst calculates the mean, median, and mode of a dataset. Which of the following best describes how these measures are used in descriptive statistics?
Easy678When creating a data story, what should be the FIRST step?
Easy679A marketing team wants to compare the growth rates of four product categories over the last quarter. Which chart type would best display this?
Easy680When communicating uncertainty in a report, which of the following is the most appropriate way to convey the reliability of a survey result showing 75% customer satisfaction?
Medium681A marketing team wants to analyze customer sentiment from social media posts. Which data acquisition method is most appropriate?
Easy682An e-commerce company is merging customer data from three legacy systems. Two systems use email as unique identifier, but one system allows multiple customers per email. The third uses phone number. To create a unified customer view, the analyst should first:
Hard683A data governance team is implementing a program to ensure consistent definitions and quality of customer data across the organization. They assign a senior manager to be accountable for the data asset. Which role does this manager fulfill?
Medium684A data analyst is preparing a presentation for executive leadership. The analyst wants to highlight the correlation between marketing spend and revenue over the past year. Which visualization type is most appropriate for showing this relationship?
Easy685In SQL, which string function would you use to remove leading and trailing spaces from a column named 'city'?
Easy686A data analyst is creating a dashboard in Tableau to monitor sales performance. The dashboard will be used by executives to quickly identify trends. Which THREE design principles should the analyst apply?
Medium687A sales dashboard shows a map with many overlapping markers in the same city, making it hard to read. What is the best improvement?
Hard688Refer to the exhibit. A database administrator notices that queries filtering on both CustomerID and OrderDate are slow. Which single change would most likely improve performance for such queries?
Hard689A data quality report shows that 95% of records have all required fields completed, but 20% of the completed fields contain values that are outside valid ranges. Which data quality dimension is most affected?
Medium690Which chart type is best for showing the number of website visitors at each stage of a conversion funnel, from initial visit to purchase?
Easy691A stock analyst is analyzing monthly sales data for a retail company and observes a consistent pattern of high sales every December. This pattern is most likely an example of which time series component?
Medium692A data team is preparing a quarterly business review for the CEO. The report must include both high-level summaries and the ability for the CEO to drill down into specific departments. Which reporting technique best meets this requirement?
Hard693Which THREE are best practices for data profiling during acquisition? (Choose three.)
Medium694In simple linear regression, the coefficient of determination R² measures:
Easy695A data analyst is using a recursive CTE to traverse an organizational hierarchy. What is the purpose of the anchor member in the recursive CTE?
Hard696A data analyst is evaluating data quality issues in a customer database. Which TWO actions are best practices for ensuring data consistency?
Hard697In a regression analysis, the coefficient of determination (R²) is 0.85. How should this value be interpreted?
Easy698A data analyst creates a report and wants to ensure it tells a compelling story. Which element is most important for data storytelling?
Medium699A data analyst is preparing a report on customer satisfaction scores. To comply with GDPR, which THREE actions must be taken? (Select THREE.)
Hard700Match each data analysis technique to its primary purpose.
Medium701A data analyst is creating a presentation for executives to explain why customer churn has increased over the last quarter. The analyst wants to present the story in a compelling way. Which narrative structure is most appropriate?
Medium702A data analyst needs to compare the salary distribution across five departments. Which visualization is most appropriate?
Medium703A data analyst wants to compare the sales revenue of five different product categories for the current month. Which chart type is most suitable for this comparison?
Easy704An analyst wants to use Python (pandas) to compute the average sales amount per region from a DataFrame 'df' with columns 'region' and 'sales'. Which TWO pandas operations are needed? (Select TWO).
Medium705In a table with columns 'employee_id' and 'manager_id', a data analyst needs to retrieve the hierarchy level of each employee, where the top manager has manager_id NULL. Which SQL feature is best suited?
Hard706A data analyst is reviewing sales data and wants to find orders where the order total is between $100 and $500, inclusive. Which WHERE clause is correct?
Medium707A sales VP wants a quick summary of last month's revenue change and key drivers. Which report section is most relevant?
Easy708A data analyst is building a binary classification model to predict customer churn. The dataset is imbalanced, with only 10% churners. The analyst wants to evaluate model performance with a focus on correctly identifying churners. Which metric is most appropriate?
Hard709A data analytics team has created a report for stakeholders. The report includes complex statistical terms and raw data tables. Stakeholders are confused and ask for clarification. Which of the following should the team do to improve communication?
Easy710A retail company wants to predict future sales based on historical data. Which modeling approach is most appropriate if the data shows a clear seasonal pattern?
Medium711A data governance team is establishing policies to ensure data quality. They define rules for data accuracy, completeness, and consistency. Which data governance function is primarily responsible for defining and enforcing these rules?
Hard712A retail company wants to segment its customers based on purchase history. Which THREE methods are appropriate for customer segmentation?
Medium713An analyst needs to create a report in Power BI that shows year-to-date sales compared to the same period last year, with the ability to drill down from year to quarter. Which DAX function combination is most appropriate for the year-to-date calculation?
Hard714The exhibit shows an SQL query executed on an 'orders' table that contains 'order_id', 'customer_id', and 'order_date'. What is the purpose of this query?
Medium715An analyst is reviewing the above SQL query used to acquire data. What does this query retrieve?
Medium716A data analyst is building a dashboard for executives and wants to ensure the most important metric, total revenue, is immediately visible. Which design principle should the analyst apply?
Medium717An analyst is preparing data for an A/B test and wants to ensure valid results. Which TWO of the following should be considered when calculating the required sample size?
Medium718A data analyst is extracting data from a web page using web scraping techniques. The data will be used for market research. Which TWO of the following are common challenges associated with web scraping?
Medium719A dataset contains sales transactions with columns 'order_date', 'amount', and 'region'. The analyst wants to calculate the total sales per region for orders placed in 2023, but only include regions where total sales exceed $10,000. Which SQL clause should be used to filter the aggregated results?
Medium720A data analyst wants to compare the means of three different training methods on employee productivity. Which statistical test is most appropriate?
Easy721A data analyst wants to retrieve the top 5 highest-paid employees from a table named 'employees' that has columns 'employee_id', 'salary', and 'name'. Which SQL query should they use?
Easy722A data team needs to communicate insights about customer churn to the sales team. The insights include confidence intervals and p-values. The sales team is not familiar with statistics. Which of the following should the data team do?
Medium723Refer to the exhibit. Which conclusion can be drawn from this data quality report?
Hard724A marketing team wants to explore the relationship between advertising spend (in dollars) and resulting revenue. Which chart type is most suitable?
Easy725A data analyst at a retail company is building a dashboard for store managers to track sales performance. The data comes from three sources: point-of-sale (POS) systems, inventory, and customer loyalty. The POS table contains columns transaction_id, store_id, date, product_id, quantity, and price. The inventory table has product_id, store_id, stock_level, and reorder_point. The loyalty table has customer_id, transaction_id, and points_earned. The analyst creates a star schema with a sales_fact fact table containing all rows from POS, dimension tables for store, product, date, and customer. To calculate average transaction value, the analyst uses the formula SUM(quantity * price) / COUNT(*). Store managers report that the average transaction value appears too low, especially for stores with multiple registers. The analyst realizes that because each product sold in a transaction creates a separate row in sales_fact, a single transaction with multiple items contributes multiple rows. The current calculation divides by the number of rows rather than the number of distinct transactions. Which of the following is the best course of action to correct the average transaction value metric? (Choose one.)
Hard726Refer to the exhibit. Which type of data is the field "region"?
Medium727A data analyst wants to show the relationship between advertising spend and sales revenue for 50 stores. Which chart type is most appropriate?
Medium728A data analyst is reviewing a dataset of customer transactions and wants to assess data quality by profiling the 'order_date' column. Which TWO profiling tasks are most appropriate for this date column? (Select TWO).
Medium729An analyst is choosing a chart to show the correlation between two continuous variables. Which TWO chart types could be used? (Select two.)
Medium730Which TWO of the following are examples of semi-structured data?
Medium731A data analyst creates a scatter plot showing the relationship between advertising spend and revenue. The plot shows a strong positive correlation. Which of the following should the analyst include in the report to ensure accurate communication?
Medium732A data analyst uses a CTE to simplify a complex query. Which keyword is used to define a CTE?
Medium733An analyst is planning an A/B test to compare two website designs. Which TWO factors should be considered when calculating the required sample size?
Medium734Which stage of the data lifecycle involves converting raw data into a usable format, such as cleaning or validating?
Easy735A data analyst wants to retrieve data from a REST API that returns JSON. Which step is part of the data lifecycle for this activity?
Medium736A hospital wants to analyze patient readmission rates. The data contains daily patient visits. What is the level of granularity?
Easy737A data analyst is cleaning a dataset with missing values in a time series of daily temperatures. The missing values occur sporadically. Which imputation method is most appropriate to maintain the temporal trend?
Hard738A retail company analyzes customer purchase data to improve inventory management. They store daily transaction records in a relational database and monthly aggregate reports in a data warehouse. Which difference between these storage methods best explains why the warehouse is more suitable for trend analysis?
Medium739A marketing team conducted a customer satisfaction survey for five different departments (Sales, Support, Billing, Shipping, Returns). The survey asked customers to rate their satisfaction on a scale of 1 (Very Dissatisfied) to 5 (Very Satisfied). The data is ordinal and the team wants to visualize the distribution of responses for each department to quickly see which department has the most 'Very Satisfied' customers and which has the most 'Very Dissatisfied'. They also want to compare the spread of responses across departments. Which chart type should they use?
Easy740An analyst writes a SQL query that uses a window function: SELECT employee_id, salary, LAG(salary, 1) OVER (ORDER BY salary DESC) AS prev_salary FROM employees. What does the LAG function return for the row with the highest salary?
Hard741An analyst is sampling a large customer database to estimate the average purchase amount. To ensure that the sample proportionally represents different customer segments (e.g., age groups), which sampling method should be used?
Medium742A data engineer is designing a system to store raw sensor data from thousands of IoT devices. The data will be used later for various analytics projects, but the schema is not yet defined. Which storage solution is most appropriate?
Hard743A company is acquiring social media data via a public API. Which TWO considerations are important for ensuring ethical and legal compliance?
Medium744An OLTP system processes thousands of transactions per second. Which property ensures that a transaction is fully completed or fully rolled back, preventing partial updates?
Medium745A data analyst is reviewing a dataset containing house prices. The mean price is $350,000 and the median is $280,000. Which of the following best describes the distribution of house prices?
Medium746A data analyst is creating a report for a marketing campaign. The campaign data includes customer names, email addresses, and purchase history. Which of the following best describes the 'customer name' data type?
Easy747Refer to the exhibit. What is the most likely cause of the extraction failure?
Hard748A retail company wants to forecast monthly sales for the next 12 months. Sales data shows a clear upward trend and seasonal patterns that repeat yearly. Which time series model is most appropriate?
Medium749In multiple linear regression, which TWO assumptions are critical for unbiased coefficient estimates? (Choose two.)
Medium750Refer to the exhibit. A stakeholder complains that the line chart exaggerates the changes in sales. What is the most likely cause?
Easy751While reviewing a dashboard, an analyst notices that the data in a trend line chart does not match the underlying data due to a filter setting. The dashboard is used for weekly executive meetings. What should the analyst do?
Hard752A data analyst needs to identify duplicate customer records. Which TWO methods are commonly used? (Select two.)
Medium753An analyst is using a CTE to compute hierarchical data. Which TWO statements about recursive CTEs are true?
Hard754A data analyst receives the above JSON snippet from a web API. The analyst needs to extract the email addresses for all customers. Which JSONPath expression should be used?
Easy755In Looker Studio, what is the difference between dimensions and metrics?
Medium756A data analyst is using a recursive CTE to traverse a hierarchical organizational chart. Which THREE components are required to define a recursive CTE? (Select THREE.)
Hard757A sales manager wants to see the conversion rates at each stage of the sales pipeline, from initial contact to closed deal. Which chart type is most appropriate?
Medium758A sales analyst wants to show total sales by product category, with each category's contribution to the total. Which chart type is best?
Easy759Which TWO of the following are primary benefits of implementing a data governance program?
Hard760A data team needs to extract data from a legacy system that only supports flat file exports. Which data acquisition method is most appropriate?
Easy761Refer to the exhibit. Which data quality dimension is compromised by the missing value for Charlie's salary?
Easy762A dashboard designer wants to highlight the sales performance of individual sales representatives compared to team averages. Which chart type is most suitable for this comparison?
Easy763An analyst is presenting a recommendation to increase marketing spend. Which statement best follows the data-driven recommendation structure (evidence → insight → recommendation → expected impact)?
Easy764Which THREE are best practices for designing a dashboard for executive consumption?
Hard765A data analyst needs to perform stratified sampling on a customer database to ensure proportional representation across three regions: North (40%), South (30%), and West (30%). The total sample size required is 1,000. How many customers should be sampled from the North region?
Hard766Which TWO of the following are appropriate uses of min-max normalisation?
Medium767A data analyst notices that a line chart showing monthly sales over the past two years has a steep drop in one month. Upon investigation, the analyst discovers that a new sales region was added mid-month and the data was not normalized. Which of the following best practices should the analyst apply to communicate this insight accurately?
Medium768A data analyst needs to create a recursive CTE to traverse a hierarchical employee-manager table. Which of the following is a key requirement for a recursive CTE?
Hard769Refer to the exhibit. A data analyst is unable to access the dataset during weekends. Based on the policy, what is the most likely reason?
Easy770A data analyst discovers that a dataset contains multiple records for the same customer with different spellings (e.g., 'Jon' vs 'John'). Which data preparation step should be applied first?
Hard771Which THREE of the following are common characteristics of unstructured data?
Medium772A data analyst is using SQL to extract data. The analyst wants to retrieve all records from a table named 'sales' where the 'amount' column is greater than 100. Which SQL clause should be used?
Easy773A data analyst needs to show the relationship between advertising spend (in dollars) and the number of website visits. Both variables are continuous. Which chart type is most suitable?
Easy774Which data quality dimension ensures that data represents the real-world scenario correctly and without errors?
Easy775A data analyst is analyzing survey responses where respondents rated satisfaction on a scale of 1-5. The analyst wants to visualize the distribution of responses. Which chart type is most appropriate?
Medium776In A/B testing, which factor is increased by having a larger sample size?
Hard777A financial analyst is creating a quarterly report compliant with SOX. Which requirement is most critical for the report's audit trail?
Hard778A data analyst wants to assign a unique sequential integer to each row in a result set, starting at 1, based on the order of the 'sales_amount' column descending. Which window function should be used?
Medium779Which type of chart is most suitable for showing the distribution of a single continuous variable?
Easy780An organization has multiple systems that store customer information inconsistently. To create a single authoritative view of customer data, they implement a process that identifies and merges duplicate records. This is an example of which data management discipline?
Hard781A data analyst needs to retrieve the top 5 most expensive products from a 'products' table sorted by price descending. Which TWO SQL clauses are required to achieve this? (Select TWO).
Easy782A table named Orders has columns OrderID, CustomerID, OrderDate, and TotalAmount. Which column should be the primary key to uniquely identify each order?
Medium783Which TWO of the following are examples of data transformation? (Choose TWO.)
Easy784A sales analyst is building a report to analyze quarterly performance. Which THREE are appropriate uses of a formula language or a data transformation tool? (Select three.)
Hard785A data analyst discovers a data discrepancy in a report that has already been distributed to executives. The discrepancy is due to a known bug that will be fixed next month. What is the most appropriate action?
Hard786A data analyst is working with a dataset that contains customer names and addresses. Some records have missing state codes. Which data quality issue is this?
Medium787A telecommunications company is experiencing issues with its customer satisfaction survey data. The data is collected from multiple channels: phone, email, and web forms. Each channel uses a different scale for ratings: phone uses 1-10, email uses 1-5, and web uses 1-7. Additionally, some survey responses contain missing values for demographic fields. The data analyst needs to calculate an overall satisfaction score that is comparable across all channels. The company's leadership wants a single metric that minimizes distortion from the different scales. Which approach should the analyst use to standardize the ratings?
Medium788You have a table 'Orders' with columns order_id, customer_id, order_date, and amount. You need to write a query that returns each customer's most recent order date and the amount for that order. Which approach is correct?
Hard789Which TWO chart types are appropriate for visualizing the distribution of a continuous variable? (Select two.)
Medium790A retail company wants to analyze customer purchase patterns to identify products frequently bought together. Which data mining technique is most appropriate?
Easy791A data analyst needs to retrieve only unique job titles from the 'employees' table. Which SQL keyword should be used in the SELECT clause?
Easy792Which THREE of the following are common steps in data cleaning?
Medium793A data analyst is designing a dashboard and wants to maximize the data-ink ratio. Which action aligns with this principle?
Medium794A data team is preparing a dashboard for executives. The team wants to highlight key performance indicators (KPIs) that are below target. Which of the following visualization techniques would most effectively draw attention to underperforming metrics without causing confusion?
Hard795A data analyst is building a dashboard that will be used by both executives and operational managers. The executives need high-level summaries, while managers need granular details. Which dashboard design principle should the analyst apply?
Hard796Which TWO of the following are examples of quantitative data? (Choose TWO.)
Medium797Match each data security concept to its description.
Medium798A company is designing a data lake to store raw sensor data from IoT devices. The data arrives as JSON objects with varying schemas. Which storage approach is most appropriate?
Hard799Which data quality dimension is violated if a customer record has a missing phone number?
Easy800A data analyst needs to combine rows from two tables based on a related column, but only wants rows that have matching values in both tables. Which join type should the analyst use?
Medium801A large e-commerce company has a data warehouse that stores daily sales transactions. The data analytics team creates a weekly report for the executive team that includes total revenue, number of orders, and average order value. Recently, the report showed a sudden 20% drop in total revenue compared to the previous week. Upon investigation, the data analyst discovers that a major promotional event ended the previous week, and the current week's data includes a new product launch with lower prices. The analyst needs to present this data to the executives in a way that accurately reflects the business situation. The analyst must also provide recommendations for actions. Which of the following is the best course of action?
Hard802A data engineer needs to store logs from web servers that have varying fields. The logs are in JSON format. Which data type describes this JSON data?
Medium803A data analyst is presenting a story about declining sales. The narrative arc should include which three elements in order?
Hard804A data analyst needs to present the distribution of customer ages to a non-technical audience. Which type of chart would be most appropriate?
Easy805A data scientist is building a classification model to predict customer churn. The dataset has 10,000 records with 500 churners. The scientist uses logistic regression and achieves 98% accuracy, but the precision for churn class is only 15%. Which of the following is the most likely cause?
Hard806A data analyst is creating a dashboard and wants to maximize the data-ink ratio. Which action supports this principle?
Medium807A retail analyst wants to visualize monthly sales over the past year to identify seasonal patterns. Which chart type is best?
Easy808An analyst wants to compare the average sales revenue across three different store locations. Which TWO statistical methods are appropriate for this comparison?
Medium809Which TWO of the following are valid SQL clauses used to filter and sort data?
Easy810Which THREE factors should be considered when choosing a chart type for a dataset?
Hard811A marketing team wants to segment customers into groups based on purchasing behavior without prior labels. Which algorithm should the data analyst use?
Medium812A data scientist creates a box plot of employee salaries and notices many outliers above the upper whisker. What action should be taken to best understand the salary distribution?
Hard813A data scientist is working with a dataset containing 1000 features and 500 samples. The goal is to build a predictive model. Which technique should be used to reduce the number of features while retaining most of the variance?
Hard814The exhibit shows a JSON configuration for a line chart that displays average response time over time. However, the chart shows jagged lines with many spikes. Which configuration change would smooth the visualization?
Medium815A company must comply with GDPR when reporting customer data. What must be included in the report?
Easy816A data analyst is using Python pandas to perform exploratory data analysis. Which THREE methods are commonly used to assess data quality and distributions?
Hard817A data analyst is troubleshooting a dashboard that displays slowly. Which two of the following are common causes of dashboard performance issues? (Select TWO.)
Medium818A data analyst wants to export a summary report from a DataFrame in pandas. Which THREE methods are commonly used for data export?
Easy819A retail company generates a daily PDF report showing the previous day's sales by region and product category. The report is automatically emailed to store managers at 6:00 AM. Which type of report is this?
Medium820A data team is creating a report for the board of directors. The board wants to see both the big picture and the ability to explore details for specific regions. Which TWO approaches should the team implement?
Hard821A data analyst is presenting a weekly sales report to a diverse audience that includes sales managers, marketing team, and finance. The analyst wants to ensure the data is understood correctly. Which communication strategy is most effective?
Hard822A financial analyst is preparing a report that must comply with the Sarbanes-Oxley (SOX) Act. What is the most critical requirement for this report?
Hard823A data analyst is presenting a recommendation to reduce inventory costs. The evidence shows that overstocking occurs in 30% of warehouses. Which of the following best structures the recommendation?
Hard824A database table has columns: OrderID (primary key), ProductID, CustomerID, CustomerName, OrderDate, ProductName. All products are purchased only by the customer who placed the order. Which normal form violation exists if CustomerName depends on CustomerID?
Hard825A data team is building a predictive model. They have data on 'Number of employees' (whole numbers) and 'Revenue' (currency). Which statement correctly compares these data types?
Medium826Drag and drop the steps to perform a data backup using the 3-2-1 rule in the correct order.
Medium827A data modeler is designing a dimensional model for a sales analytics system. The fact table contains sales transactions, and the dimension tables include product, customer, and time. To reduce data redundancy, the modeler normalizes the dimension tables into multiple related tables. Which schema is being implemented?
Hard828The exhibit shows log entries. A data analyst wants to visualize the frequency of each error type over time. Which chart type is most appropriate?
Easy829A data analyst is troubleshooting a dashboard that displays incorrect totals for sales by region. The data source queries are correct. Which of the following is the most likely cause?
Medium830An analyst is creating an executive summary for a quarterly business review. Which THREE components are essential for an effective executive summary?
Hard831Which TWO of the following are characteristics of OLTP systems? (Select 2)
Easy832A data engineer needs to extract data from a REST API and load it into a data warehouse. The data is received in JSON format. Which data type best describes JSON?
Easy833A data analyst needs to combine two datasets that have the same columns but different rows. Which operation should they use?
Easy834An analyst recommends a pricing change based on data showing price elasticity. The recommendation includes expected revenue impact. What is this an example of?
Medium835In a simple linear regression model y = 2.5 + 1.2x, what is the predicted value of y when x = 10?
Easy836A data analyst wants to show the monthly sales trend for the past two years with an emphasis on cumulative growth. Which chart type is most appropriate?
Medium837Refer to the exhibit. A data analyst is unable to run a query on the customers table after October 1, 2023. What is the reason?
Hard838A dashboard needs to show sales trends for each of five regions over the past year. The intended audience wants to compare trends easily. Which chart type is best?
Easy839In the data lifecycle, which phase involves converting raw data into a usable format for analysis?
Hard840A data analyst wants to segment customers based on purchasing behavior such as frequency, monetary value, and recency. Which TWO clustering evaluation methods can help determine the optimal number of clusters? (Select two.)
Medium841A database has a table that violates 2NF because it contains a composite primary key and some attributes depend only on part of that key. Which normal form would be violated next if the table is not addressed?
Hard842A data analyst is asked to compare the average sales across three different store locations. The data is normally distributed and variances are approximately equal. Which statistical test is most appropriate?
Hard843Which TWO of the following are best practices for designing a data dashboard?
Medium844A healthcare database stores patient records. Each patient has a unique patient_id, and the database includes a table 'visits' with visit_id, patient_id, visit_date, and diagnosis_code. To ensure data integrity, which constraint should be applied to the patient_id column in the 'visits' table?
Easy845An analyst is performing a logistic regression to predict customer churn (yes/no). The model outputs a probability of 0.75 for a particular customer. Which of the following best describes the interpretation?
Hard846A data analyst needs to create a dashboard that updates automatically every hour. The data source is a large database. Which approach minimizes performance impact?
Medium847Which THREE of the following are valid data quality dimensions? (Choose THREE.)
Hard848An operations manager needs to monitor manufacturing line status every 15 minutes to identify bottlenecks. Which type of report should be used?
Easy849An analyst is conducting an A/B test on a new checkout process. To calculate sample size, which THREE factors must be considered?
Medium850A data engineer is tasked with acquiring data from a third-party vendor that provides daily file drops via SFTP. The files are large (10 GB each). The pipeline must load data into a data warehouse. Which approach optimizes for speed and reliability?
Hard851Refer to the exhibit. A data analyst is reviewing a data quality report. Which of the following actions should the analyst take first?
Hard852A healthcare organization must ensure patient data privacy when sharing reports with external auditors. Which practice is most important?
Hard853A data analyst wants to retrieve the top 5 highest-paid employees from the 'employees' table. Which SQL clauses could be used to achieve this? (Select TWO.)
Medium854A data analyst is preparing a presentation for the executive team to explain why quarterly revenue fell short of targets. They want to use storytelling with data. Which THREE elements should be included in the narrative arc? (Choose three.)
Hard855A manufacturing company has two primary data systems: an ERP system that stores production orders with fields like OrderID, ProductID, Quantity, and ProductionDate, and a CRM system that stores customer sales with fields like SaleID, CustomerID, ProductID, SaleDate, and Amount. The data analyst needs to create a unified view of product performance by joining these tables. However, the ProductID field in the ERP uses a 5-character alphanumeric code (e.g., 'P1234'), while the CRM uses a 6-character code (e.g., 'PR1234'). Additionally, some products have multiple entries due to slight variations in naming. The analyst wants to ensure accurate matching without losing data. Which action should the analyst take first to address the data inconsistency?
Medium856A data analyst needs to visualize the distribution of a continuous variable across different categories. Which chart type is most suitable?
Medium857During a presentation, a stakeholder questions the validity of a data insight because the sample size appears small. The analyst knows the sample is statistically significant. What is the best way to address this concern?
Hard858A data analyst is designing a dashboard for executives. Which best practice should be followed?
Medium859A business user wants to explore sales data without relying on the data team. Which report type empowers the user to create their own analysis?
Easy860A data analyst is profiling a new dataset containing customer information. When assessing data quality, which metric would be most appropriate to determine if the 'email' column contains valid email addresses?
Medium861An analyst is presenting findings to a non-technical audience. The data shows a 20% increase in customer churn after a price change. Which presentation approach is BEST?
Medium862A data analyst is using the IQR method to identify outliers in a dataset. The first quartile (Q1) is 25 and the third quartile (Q3) is 45. What is the upper bound for identifying outliers?
Hard863A data analyst is performing data cleaning. Which THREE steps are part of this process? (Choose three.)
Hard864A data analyst sees this error in the ETL logs. What is the most likely cause?
Hard865Which THREE of the following are characteristics of a relational database?
Medium866Drag and drop the steps to resolve data integration conflicts in the correct order.
Medium867A company uses an OLTP system for processing customer transactions. Which characteristic is most important for this system to ensure that each transaction is processed reliably, even if multiple users access the system simultaneously?
Medium868A data analyst wants to visualize the distribution of employee salaries across departments and identify any outliers. Which chart type would best show quartiles, median, and potential outliers?
Medium869A data analyst is preparing a report to present to a mixed audience of technical and non-technical stakeholders. Which THREE techniques should the analyst use to ensure effective communication? (Choose three.)
Medium870An analyst creates a scatter plot with three variables: X, Y, and a third variable represented by the size of the markers. This chart is called a:
Hard871Which statistical test should be used to determine if there is a significant association between two categorical variables, such as gender and product preference?
Easy872A data analyst uses the following query: SELECT department, AVG(salary) AS avg_salary FROM employees GROUP BY department HAVING AVG(salary) > 50000. What is the purpose of the HAVING clause in this query?
Medium873A data analyst needs to display the distribution of customer ages in a dataset. The ages range from 18 to 85, and the analyst wants to see the shape of the distribution and identify any outliers. Which chart type should be used?
Medium874After merging two datasets, an analyst finds that the resulting dataset has many null values in some columns. Which TWO steps should the analyst take to address this? (Select two.)
Hard875A table Orders has OrderID (primary key), CustomerID, and CustomerEmail. During analysis, it is found that CustomerID uniquely identifies CustomerEmail. Which normal form is violated if both CustomerID and CustomerEmail are stored in this table?
Hard876A data analyst runs the following query: SELECT DISTINCT city FROM customers. What is the primary purpose of using the DISTINCT keyword in this query?
Easy877A dashboard designer is creating a KPI dashboard for executives. Which of the following is a leading indicator?
Medium878A data scientist runs a linear regression model to predict customer spending based on income. The R-squared value is 0.45 and the p-value for the slope coefficient is 0.03. At a significance level of α=0.05, which of the following conclusions is correct?
Hard879A company is implementing a data lifecycle management policy. Which stage occurs immediately after data is created?
Medium880Which TWO of the following are examples of unstructured data? (Select 2)
Medium881A financial analyst at a bank is preparing a report on loan default risks to the risk management committee. The committee includes both technical (quantitative analysts) and non-technical (business managers) members. The analyst has built a logistic regression model that outputs probability scores for default. The model's performance is good, but the committee wants to understand the key drivers of default. The analyst needs to communicate both the model's accuracy and the impact of each feature. The report should be concise and persuasive, leading to policy changes. What is the best approach?
Hard882Which THREE are considered best practices in dashboard design? (Select three.)
Hard883A data analyst wants to compare the revenue across five different product categories. Which chart type is best suited?
Easy884A data analyst is using Power BI to create a report that shows sales by region. The data includes duplicate rows for some transactions due to a data entry error. The analyst needs to count only unique transactions. Which DAX function should be used to create a measure for unique count?
Hard885A data analyst is building a linear regression model to predict sales based on advertising spend. The analyst notices that the residuals are not normally distributed and have a non‑constant variance. Which of the following transformations is most appropriate to apply to the dependent variable?
Easy886A data architect needs to store raw data from various sources, including social media feeds and log files, for future analysis. The data may be used for machine learning and ad-hoc queries. Which storage solution is most appropriate for storing raw data in its native format?
Easy887A data analyst is tasked with collecting data from multiple spreadsheets provided by different departments. Each spreadsheet has different column names and formats. What is the best first step?
Easy888A data analyst notices that customer addresses in the database contain invalid ZIP codes. Which data quality dimension is being violated?
Easy889An analyst is creating a report to show the relationship between advertising spend and website traffic over the past 12 months. The data has a few outliers due to special promotional events. Which chart type should the analyst use to clearly show the trend while minimizing the impact of outliers?
Medium890A data analyst uses a CTE to find employees who earn more than the average salary in their department. Which SQL clause is used to define the CTE?
Medium891Which data quality dimension is most concerned with whether data values fall within a defined domain or acceptable range?
Easy892In Tableau, a data analyst creates a calculated field to compute the average sales per customer. The analyst wants this calculation to remain constant regardless of the level of detail in the view. Which Tableau feature should be used?
Hard893A data scientist applies K-means clustering to a customer dataset. The elbow method suggests using 4 clusters. After running K-means with k=4, the within-cluster sum of squares (WCSS) is plotted against k, and the elbow is at k=4. What does this indicate?
Hard894Refer to the exhibit. What is the best corrective action to resolve this error?
Hard895Which THREE of the following are properties of ratio data? (Choose THREE.)
Hard896A data analyst is examining the relationship between advertising spend (in thousands) and sales (in thousands). The Pearson correlation coefficient is computed as r = -0.85. Which of the following interpretations is correct?
Medium897A data analyst needs to calculate the running total of sales for each product over time. Which window function clause is essential for this calculation?
Hard898A data analyst trains a complex model that achieves 99% accuracy on training data but only 65% on new data. What is the most likely issue?
Hard899An e-commerce company is acquiring product data from multiple supplier APIs. The APIs return JSON with inconsistent field naming conventions. Which data acquisition technique should be applied?
Medium900A data analyst is cleaning a dataset and finds that the 'age' column has several missing values. Which of the following is a valid method for handling missing numerical data?
Easy901A dataset contains transaction amounts with a few extremely high values. The analyst wants to reduce the impact of these outliers on the average. Which measure of central tendency is most robust?
Hard902A data analyst is using Tableau to build a dashboard. Which THREE features are available in Tableau for creating interactive dashboards?
Medium903A dataset contains a column 'Education Level' with values: 'High School', 'Bachelor', 'Master', 'PhD'. An analyst computes the average by assigning numbers 1-4. Which data concept is being violated?
Hard904During exploratory data analysis, you calculate the IQR for a numeric column and find that several data points fall below Q1 - 1.5*IQR. These points are likely:
Medium905You are a data analyst at a retail company. Your team has deployed a new dashboard that displays real-time inventory levels across all warehouses. The dashboard uses a traffic light color scheme (green = sufficient, yellow = low, red = out of stock). After one week, the warehouse managers complain that the dashboard is overwhelming because it shows all 500+ products at once, and they cannot quickly identify which items need immediate attention. They request a way to prioritize items that are red or yellow. Additionally, the dashboard updates every second, causing the screen to flicker constantly, which they find distracting. You need to redesign the dashboard to address these issues. Which course of action should you take?
Hard906A hospital's analytics team has created a dashboard for tracking patient wait times across departments. The dashboard uses a stacked bar chart showing average wait time per department, with each bar segmented by severity level (Low, Medium, High). However, management complains that it is difficult to compare total wait times across departments or identify which department has the highest average wait time. The data itself is accurate and complete. The analyst needs to redesign the visualization to address these concerns. Which course of action should the analyst take?
Hard907A data analyst is summarizing the central tendency of a dataset with extreme outliers. Which measure is most robust to outliers?
Easy908A data analyst is working with a dataset containing customer information. The dataset includes a column 'full_name' which stores first and last names together. To perform analysis on first names separately, which data concept describes the process of splitting 'full_name' into 'first_name' and 'last_name'?
Easy909An analyst is creating a report that includes multiple charts. To ensure the audience quickly grasps the key insight, which principle of data storytelling should be applied?
Medium910Which TWO are valid data acquisition methods? (Select two.)
Medium911You are using pandas in Python to clean a dataset. You notice several rows with missing values in the 'age' column. Which method would you use to remove those rows?
Easy912A data analyst is creating a report on customer satisfaction scores. The analyst wants to ensure that regional managers can only see data for their own region. Which security measure should be applied?
Medium913A database administrator is designing a normalized database to reduce data redundancy. They have a table with columns: OrderID, ProductID, ProductName, and Quantity. The table is currently in 1NF. To move to 2NF, which issue must be resolved?
Medium914A data analyst is cleaning a dataset and finds that a numeric field has several missing values. The variable is normally distributed. Which imputation method is most appropriate?
Medium915Which TWO of the following are best practices when creating a data visualization for a presentation to stakeholders?
Hard916A data analyst is designing a database for a retail application. Which TWO of the following are valid reasons to use a NoSQL document database like MongoDB instead of a relational database? (Select 2)
Hard917A data analyst calculates the mean, median, and mode of a dataset. Which of the following measures of central tendency is least affected by extreme outliers?
Easy918A data analyst uses the elbow method to determine the number of clusters for k-means. The plot shows a sharp bend at k=3 and a small bend at k=5. What is the recommended number of clusters?
Hard919An analyst is creating a data story about the decline in customer satisfaction scores. The data shows that satisfaction dropped after a software update. Which narrative structure best helps the audience understand the cause and effect?
Hard920Match each data type to its example.
Medium921A hospital's patient records system must process thousands of small transactions per second. Which type of database system is best suited for this workload?
Easy922Which TWO data types are considered quantitative? (Select two.)
Medium923A data analyst is creating a report in Power BI and needs to calculate the total sales for the current year and the previous year. Which TWO DAX functions can be used to retrieve the previous year's sales?
Hard924A data scientist has a dataset with 50 variables and wants to identify clusters of similar observations. Which visualization technique is most suitable for reducing dimensionality to 2D while preserving cluster structure?
Hard925An analyst needs to compute a running total of sales for each department, ordered by date. Which window function is most appropriate?
Hard926An e-commerce company wants to provide real-time personalized product recommendations based on customer browsing behavior. Currently, they have a traditional data warehouse that processes batch updates every night. The marketing team complains that recommendations are outdated within hours because customers see yesterday's data. The data engineer needs to modify the architecture to support near-real-time analytics. The budget is limited, and the existing warehouse infrastructure must be reused as much as possible. Which architectural change would best meet the requirement?
Easy927A data analyst is performing hypothesis testing to compare the mean sales of two store locations. Which TWO conditions must be satisfied to use a two‑sample t‑test? (Select TWO.)
Medium928A data analyst is performing data profiling on a customer table. Which metric provides the number of unique values in a column?
Medium929An analyst is performing a linear regression and obtains an R-squared value of 0.85. Which of the following is the best interpretation?
Medium930A data analyst is working with a relational database that contains a table of customer orders. To optimize query performance for a report that filters by order date and customer ID, the analyst wants to create an index. Which type of index would be most effective for queries that filter on both columns?
Hard931After presenting a data analysis to stakeholders, they ask for additional details on a specific trend. The analyst needs to provide a follow-up report. What is the best approach?
Medium932An analyst creates a histogram of customer transaction amounts but observes that the distribution looks bimodal. Upon review, the analyst realizes that two different customer segments (retail and wholesale) were combined. Which action best addresses this?
Hard933A data analyst is building a self-service reporting environment. Which of the following is the primary benefit of this approach?
Medium934Refer to the exhibit. An ETL pipeline failed. What is the most likely root cause?
Easy935A data scientist is building a model to predict customer churn (yes/no). After training a logistic regression model, the coefficient for 'monthly charges' is 0.05 with a p-value of 0.03. Which interpretation is correct at α=0.05?
Hard936A retail company has merged with another firm and now needs to create a unified customer data warehouse. The existing systems use different data classification methods: System A stores customer income as a categorical range (e.g., '$0-$50k', '$50k-$100k', '$100k+') while System B stores exact income as a decimal number. A data analyst must combine these into a single table. The goal is to perform statistical analysis that includes calculating average income, but the categorical data from System A loses precision. The analyst proposes converting System B's exact values into the same ranges as System A to ensure consistency. However, the data governance team wants to preserve as much detail as possible. Which course of action should the analyst recommend?
Hard937Drag and drop the steps to normalize a database table from 1NF to 3NF in the correct order.
Medium938A data analyst is performing K-means clustering on customer data. Which THREE of the following are steps in the K-means algorithm?
Hard939A dataset contains a column 'Age' with values: [22, 25, 25, 30, 35, 40, 45]. What is the interquartile range (IQR)?
Easy940A data analyst is conducting an A/B test on a website's landing page. The null hypothesis is that there is no difference in conversion rates between the control and treatment groups. After collecting data, the analyst calculates a p-value of 0.03. Using a significance level of α = 0.05, what is the correct conclusion?
Medium941A data analyst creates a report showing sales by product category. The analyst notices that one category has a very high sales figure due to a one-time bulk order. Which of the following is the best way to communicate this insight to stakeholders?
Medium942A dashboard designer is creating a sales performance dashboard and wants to minimize non-data ink to improve clarity. Which action best follows the principle of maximizing the data-ink ratio?
Medium943You are a data analyst at a logistics company. You have created a dashboard to monitor delivery performance. The dashboard includes a scatter plot showing delivery time (hours) vs. distance (miles) for each delivery, with points colored by delivery region (A, B, C, D, E). Users have reported that the scatter plot is cluttered because there are over 10,000 points, making it hard to see patterns. Additionally, the color legend for the five regions uses similar shades of blue, making it difficult to distinguish which region a point belongs to. You need to improve the scatter plot to reduce overplotting and improve region differentiation. Which approach is most effective?
Medium944An organization uses a data warehouse for analytics. The data team wants to load data from source systems into the warehouse. They choose to load raw data first and then perform transformations within the warehouse. Which approach are they using?
Medium945A data analyst receives a dataset with inconsistent date formats (e.g., "01/02/2023", "2023-01-02", "Jan 2, 2023"). Which data quality dimension is most directly affected?
Medium946An analyst creates a dashboard with a large amount of decorative graphics and background images. According to CompTIA Data+, which design principle is being violated?
Hard947A data governance team is establishing policies. Which three activities are part of data governance? (Select THREE.)
Hard948A dataset contains salaries ranging from $25,000 to $2,500,000, with most salaries under $100,000. Which chart type best shows the distribution without distortion from extreme values?
Hard949A data analyst is performing data acquisition from multiple source files. Which TWO data profiling tasks should the analyst complete before loading the data into the target system?
Easy950A small business wants to acquire customer feedback through a short questionnaire emailed after purchase. Which data acquisition method does this represent?
Easy951Refer to the exhibit. A data architect is designing a data dictionary for a relational database. Based on the exhibit, which data concept is being illustrated?
Hard952Which TWO of the following are true about correlation and causation? (Select TWO).
Easy953A data analyst is using a public API to collect historical weather data. The API has a rate limit of 100 requests per minute, but the analyst needs to retrieve 10,000 records as quickly as possible. What strategy should be used?
Hard954A business analyst needs to show the monthly sales trend for the past three years. Which chart type is most appropriate?
Medium955Refer to the exhibit. A data analyst is trying to extract data from a SQL Server database but receives the error. Which configuration change should the analyst recommend to the database administrator?
Medium956A data analyst is using a window function to assign a unique rank to each employee within their department based on salary, with ties receiving the same rank and leaving gaps. Which function should be used?
Hard957A retail company operates 50 stores across the country. The data analyst has been asked to create a dashboard to visualize monthly sales trends over the past two years and compare the performance of the top 5 stores. The dataset includes store name, date, and daily sales amount. Initial exploration reveals that some stores have missing sales data for certain months due to system outages, and there are occasional extreme values caused by promotional events (e.g., Black Friday sales are 10x normal). The analyst needs to choose an appropriate visualization approach that accurately represents the trends and comparisons while handling these data quality issues. What should the analyst do to best meet the requirements?
Easy958A data scientist is preparing data for a K-means clustering algorithm. The dataset contains features measured in different units (e.g., income in dollars and age in years). Which preprocessing step is most critical before running K-means?
Medium959A large online retailer stores customer orders in a PostgreSQL database. Each order has a unique order ID, and the database is normalized to 3NF. Which type of data is this?
Medium960A business analyst wants to show the relationship between advertising spend (independent variable) and sales revenue (dependent variable) for 12 different regions. Each region will be represented by a point. Which chart type is most appropriate?
Medium961An analyst is fitting a polynomial regression model and wants to choose the degree that minimizes overfitting. Which technique should the analyst use?
Hard962A company is merging two customer databases from different acquisitions. They need to identify duplicate records. Which data profiling technique is most effective?
Medium963A data analyst is presenting results from a customer segmentation analysis to a non-technical audience. The segmentation was performed using k-means clustering, and the analyst wants to explain the characteristics of each cluster. Which visualization is most appropriate for this audience?
Hard964Drag and drop the steps to clean a dataset with missing values in the correct order.
Medium965A data scientist is building a predictive model to forecast monthly sales. The data shows a linear trend with no seasonality. Which regression technique is most appropriate?
Medium966A data engineer is designing an ETL pipeline to extract sales data from a legacy on-premise database and load it into a cloud data warehouse. The database is slow and queries during business hours affect performance. Which extraction strategy minimizes impact?
Medium967A retail company has a dashboard that tracks daily sales across all stores. The dashboard is used by the CEO during monthly board meetings. Recently, the CEO complained that the dashboard is confusing and takes too long to interpret. The data analyst is asked to redesign the dashboard to improve usability. The analyst has access to all sales data. The CEO prefers a high-level overview with the ability to drill down into regions if needed. The analyst must decide on a course of action. What should the analyst do first?
Easy968In a logistic regression model predicting customer churn (1 = churn, 0 = not churn), the coefficient for 'contract length' is -0.5. Which of the following is the correct interpretation?
Medium969A data analyst is performing exploratory data analysis on a dataset containing house prices. They want to identify outliers in the 'price' column using the IQR method. The first quartile (Q1) is $200,000, the third quartile (Q3) is $350,000, and the IQR is $150,000. What is the upper bound for identifying outliers?
Medium970Drag and drop the steps to perform a root cause analysis on data quality issues in the correct order.
Medium971An analyst notices that a dashboard displays conflicting data from two sources. What is the first step in troubleshooting?
Hard972A data analyst is using SQL to filter a sales table for transactions that occurred in either 'Q1' or 'Q3' of 2023 and have a sale amount greater than $100. Which WHERE clause correctly implements this condition?
Medium973A data analyst needs to share a weekly sales report with the marketing team. The report includes aggregated data from the data warehouse. To simplify access, the analyst creates a virtual table that encapsulates the complex query. Which database object should the analyst create?
Medium974Based on the exhibit, what is the most likely cause of the import failure?
Hard975A data analyst is designing a dashboard for executives. Which TWO practices improve dashboard effectiveness? (Select two.)
Medium976A data analyst needs to show the relationship between advertising spend (in dollars) and monthly sales revenue (in dollars) for the past 12 months. Which chart type is most appropriate?
Medium977A data analyst discovers that the sales data for the current quarter shows a 15% increase in revenue. However, the analyst notes that the data does not include returns from the last week due to a system lag. How should the analyst communicate this uncertainty?
Medium978Which database index type is most commonly used for exact-match lookups and range queries in a B-tree structure?
Easy979A data analyst is preparing a dataset for analysis and needs to handle outliers. Which TWO of the following are common methods for treating outliers?
Medium980A data analyst is using pandas to clean a DataFrame that contains missing values in the 'age' and 'income' columns. Which THREE pandas methods are appropriate for handling missing data? (Select THREE).
Easy981A healthcare analytics team is analyzing patient readmission rates. They have a dataset with thousands of records including patient age, diagnosis, length of stay, number of prior admissions, and discharge date. The goal is to identify key factors influencing readmission and create a model to predict high-risk patients. The data is imbalanced: only 5% of patients are readmitted within 30 days. The team plans to use logistic regression. What is the most appropriate approach?
Medium982An e-commerce company wants to analyze sales performance across product categories. The dataset includes transaction amounts and a column 'category' with values (Electronics, Clothing, Home). The analyst decides to use stratified sampling to ensure proportional representation. Which THREE steps are required to implement this? (Select THREE).
Hard983A data analyst wants to find customers whose last name starts with 'Mc' and have made purchases in 2023. The purchase table has a purchase_date column. Which SQL query accomplishes this?
Medium984A data engineer is designing a data warehouse for a multinational corporation. The company has sales data from different regions with varying currencies and date formats. To ensure consistency, which data concept should be applied to standardize the data before loading into the warehouse?
Hard985A data analyst calculates the mean, median, and mode of a sales dataset and finds they are all equal. Which type of distribution does this indicate?
Easy986A logistics company is analyzing truck delivery times. Which variable is discrete?
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Frequently asked questions
- What does the software troubleshooting domain cover on the DA0-002 exam?
- software troubleshooting questions test whether you can apply the concept in context, not just recognise a definition.
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- This page lists all 986 software troubleshooting questions in the DA0-002 question bank. The actual exam draws from this domain proportionally to its weighting in the official exam blueprint.
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