DA0-002 Practice Test 47 — 15 Questions

Question 1

A 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?

Accepted Answer

Bar chart. A bar chart is ideal for comparing discrete categories across a single metric like sales revenue.

Answer

Histogram

Answer

Pie chart

Answer

Line chart

Question 2

A sales analyst wants to show total sales by product category, with each category's contribution to the total. Which chart type is best?

Accepted Answer

Stacked bar chart. A stacked bar chart shows both the total and the part-to-whole breakdown by category.

Answer

Scatter plot

Answer

Box plot

Answer

Line chart

Question 3

A 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?

Accepted Answer

Join. (Join) because the scenario describes combining data from two different sources—MySQL and MongoDB—into a unified view using a SQL query that joins the tables after extraction. This is a classic example of a cross-source join, where data from disparate databases is merged based on a common key, which is the fundamental purpose of a JOIN operation in SQL.

Answer

View

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Stored procedure

Answer

Index

Question 4

A data analyst is designing a dashboard and wants to maximize the data-ink ratio. Which action aligns with this principle?

Accepted Answer

Removing unnecessary gridlines. Data-ink ratio focuses on removing non-data ink (chartjunk) and emphasizing data. Using minimal gridlines reduces non-data ink.

Answer

Using 3D effects for bars

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Adding a background image

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Using bright colors for all elements

Question 5

A 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.)

Accepted Answer

Resolution: the recommended action or outcome. Situation sets context, complication introduces the problem, and resolution provides the solution. Data details are not part of the high-level narrative arc.

Answer

Raw data tables with every transaction

Answer

Detailed explanation of data cleaning steps

Question 6

A 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?

Accepted Answer

Box plot. A box plot displays the median, quartiles (Q1 and Q3), and outliers, making it ideal for identifying outliers in distribution.

Answer

Heat map

Answer

Histogram

Answer

Scatter plot

Question 7

A 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?

Accepted Answer

DATEADD. SAMEPERIODLASTYEAR and DATEADD (with -1 year) both can return dates from the previous year. PREVIOUSYEAR is invalid, TOTALYTD is for current year, and FILTER is not a time intelligence function.

Answer

TOTALYTD

Answer

FILTER

Answer

PREVIOUSYEAR

Question 8

A 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?

Accepted Answer

Self-service report. Self-service reporting allows business users to create their own reports and visualizations using BI tools without technical skills.

Answer

Operational report

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Scheduled report

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Ad hoc report

Question 9

A 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?

Accepted Answer

Incorporate conditional formatting with color alerts.. Conditional formatting with color alerts (e.g., red for critical thresholds, yellow for warnings) directly addresses the executives' need to quickly identify critical issues at a glance. This design change leverages pre-attentive visual processing, allowing users to spot anomalies without manually scanning each KPI. It is a standard best practice in dashboard design for executive reporting, as it reduces cognitive load and speeds up decision-making.

Answer

Use a single aggregated metric to simplify.

Answer

Increase the refresh rate to every hour.

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Add more detailed charts to each KPI.

Question 10

A financial institution needs to acquire credit transaction data from multiple sources while ensuring compliance with data privacy regulations. What is the most critical step?

Accepted Answer

Data anonymization during extraction. Data anonymization during extraction is the most critical step because it ensures that personally identifiable information (PII) is irreversibly masked or removed before the data enters the processing pipeline, directly addressing compliance with regulations such as GDPR and PCI DSS. Without this step, even if other measures are applied later, the initial exposure of sensitive data violates privacy mandates and increases breach risk.

Answer

Data replication for redundancy

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Data enrichment with external sources

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Data compression for storage

Question 11

A 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?

Accepted Answer

Create a line chart with month on the x-axis, sales on the y-axis, and separate lines for each region and category; check for outliers and consider annotating them. A line chart with month on the x-axis and separate lines for each region and product category allows clear visualization of sales trends over time for each combination. This approach also suggests checking for outliers (e.g., grand opening spikes) and annotating them rather than removing them, preserving valuable data. Option A is incorrect: a stacked bar chart with all stores aggregated per month obscures individual category and regional trends, making it hard to identify which categories are driving growth. Option C is incorrect: removing outlier stores discards legitimate data from grand opening events, which may be important for understanding growth. Option D is incorrect: a scatter plot is not suitable for showing time series trends as it does not connect points sequentially and makes trend identification difficult.

Answer

Use a stacked bar chart showing total sales by month, with each bar segmented by region and category

Answer

Create a scatter plot of sales vs. month with dots colored by region

Answer

Remove all stores with outlier sales and then create a line chart of the cleansed data

Question 12

When presenting data insights to a technical audience, which of the following is most important to include?

Accepted Answer

Details on data sources, transformations, and methodology.. For a technical audience, the most important element is transparency in data provenance and methodology, as they need to assess the validity and reproducibility of the analysis. Including details on data sources, transformations, and methodology allows them to verify assumptions, identify potential biases, and understand the analytical pipeline. This aligns with the DA0-001 domain of Communicating Data Insights, where technical stakeholders require rigorous documentation over persuasive elements.

Answer

A call to action for the next steps.

Answer

Colorful charts and infographics.

Answer

High-level summaries and executive recommendations.

Question 13

A 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?

Accepted Answer

One or more predictors may not be contributing meaningfully. Adjusted R-squared penalizes for adding predictors that do not improve the model significantly; a gap suggests some predictors may be irrelevant or the sample size is small.

Answer

The model is overfitted, so all predictors should be removed

Answer

The model has high multicollinearity

Answer

The residuals are not normally distributed

Question 14

An analyst calculates a Pearson correlation coefficient of -0.8 between advertising spend and customer churn rate. Which interpretation is correct?

Accepted Answer

Increasing advertising spend is associated with decreasing churn rate.. Negative correlation means as one variable increases, the other decreases; strength is high (close to -1).

Answer

There is a weak positive relationship.

Answer

Advertising spend causes churn to decrease.

Answer

64% of the variance in churn is explained by spend.

Question 15

In 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?

Accepted Answer

$140,000. Using y = mx + b, predicted price = 30000 * 3 + 50000 = $140,000.

Answer

$80,000

Answer

$150,000

Answer

$90,000