DA0-002 Practice Exam 3 — 20 Questions

Question 1

A data analyst is creating a self-service reporting environment. Which data governance practice ensures users see only data relevant to their department?

Accepted Answer

Row-level security. Row-level security restricts data access based on user roles, ensuring users only see authorized data.

Answer

Data lineage

Answer

Data dictionary

Answer

Single version of truth

Question 2

Which TWO are common pitfalls when communicating data insights?

Accepted Answer

Using misleading scales on charts. Using misleading scales on charts (e.g., truncating the y-axis or using non-zero baselines) distorts the visual representation of data, leading to incorrect interpretations. This violates the principle of data integrity in data visualization, as it can exaggerate or minimize trends, making it a common pitfall when communicating data insights.

Answer

Explaining assumptions clearly

Answer

Including a clear call to action

Answer

Providing context for the data

Question 3

A 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?

Accepted Answer

There is a strong positive linear relationship.. r = +0.92 indicates a strong positive linear relationship.

Answer

There is a strong negative linear relationship.

Answer

There is no linear relationship.

Answer

92% of the variation in revenue is explained by advertising spend.

Question 4

A 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?

Accepted Answer

$575,000. The IQR method defines outliers as values below Q1 - 1.5*IQR or above Q3 + 1.5*IQR. Upper bound = 350,000 + (1.5 * 150,000) = 350,000 + 225,000 = $575,000.

Answer

$500,000

Answer

$425,000

Answer

$650,000

Question 5

A 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?

Accepted Answer

Correct the previous month's data, recalculate the change, and present the increase alongside an explanation of the new program and the data correction.. The best course of action because it addresses both the data quality issue and the business concern. By correcting the previous month's erroneous discharge dates, the analyst recalculates the true baseline, ensuring the reported increase in average length of stay is accurate. Presenting the corrected data alongside an explanation of the new chronic disease management program provides a complete, transparent narrative that separates the impact of the data error from the program's effect, which is essential for informed decision-making by hospital administrators.

Answer

Correct the previous month's data and present the adjusted increase, emphasizing the data error.

Answer

Present the raw data as-is and explain that the increase is due to the new program.

Answer

Delay the report until the next month to gather more data on the program's effect.

Question 6

A data analyst wants to extract the year from a date column 'order_date' in a SQL database. Which function should be used?

Accepted Answer

YEAR(order_date). The YEAR() function extracts the year from a date. DATEADD adds intervals, DATEDIFF calculates differences, GETDATE() returns current date.

Answer

DATEADD(year, order_date, 0)

Answer

DATEDIFF(year, order_date, GETDATE())

Answer

GETDATE()

Question 7

An analyst notices that a dashboard displays conflicting data from two sources. What is the first step in troubleshooting?

Accepted Answer

Check data transformation steps and join logic. The first step in troubleshooting conflicting data from multiple sources is to verify the data transformation steps and join logic. Conflicts often arise from incorrect joins (e.g., using INNER JOIN instead of LEFT JOIN), mismatched keys, or data type conversions that alter values. Checking these steps isolates the root cause before any other action, such as re-running queries or notifying stakeholders.

Answer

Re-run all queries

Answer

Notify stakeholders of potential error

Answer

Replace the data source with the one believed to be correct

Question 8

Based on the exhibit, what is the most likely cause of the import failure?

Accepted Answer

A data quality issue: the date field contains an invalid date.. The exhibit shows a date field containing '2023-02-30', which is an invalid date (February never has 30 days). This data quality issue causes the import to fail, as the system likely validates date values against calendar rules before inserting them into the target table. The error is not due to file emptiness, non-numeric characters, or corruption, but specifically a semantic data integrity violation.

Answer

The file is empty or contains only headers.

Answer

The price field includes non-numeric characters that cannot be parsed.

Answer

The source file is corrupted or in an unsupported format.

Question 9

A 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?

Accepted Answer

View. A view is a virtual table that encapsulates a complex query, allowing users to access aggregated data without needing to understand the underlying SQL. In this scenario, the analyst creates a view to simplify access to the weekly sales report, as it presents pre-defined, aggregated data from the data warehouse as if it were a table.

Answer

Trigger

Answer

Stored procedure

Answer

Index

Question 10

Refer to the exhibit. What data quality issue is indicated?

Accepted Answer

Non-standardized data entry. The error shows that a non-numeric value 'N/A' is present in a numeric column, indicating non-standardized data entry. Duplication, inconsistency, or outliers are not directly shown.

Answer

Data inconsistency

Answer

Outlier

Answer

Data duplication

Question 11

A data governance team is defining roles and responsibilities for data management. Which TWO of the following are common data governance roles? (Select TWO).

Accepted Answer

Data steward. Data owner and data steward are standard roles in data governance, responsible for data ownership and stewardship respectively.

Answer

Data scientist

Answer

Database administrator

Answer

Data analyst

Question 12

A 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?

Accepted Answer

Min-max normalization. Min-max normalization rescales features to a fixed range (e.g., 0 to 1), making distances computed equally weighted. Standardization is better for algorithms assuming Gaussian distributions.

Answer

Z-score standardization

Answer

One-hot encoding

Answer

Log transformation

Question 13

A 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?

Accepted Answer

Scatter plot. A scatter plot is used to visualize the correlation between two continuous variables.

Answer

Line chart

Answer

Bar chart

Answer

Pie chart

Question 14

A data analyst needs to identify the most frequently occurring value in a dataset. Which measure of central tendency should they use?

Accepted Answer

Mode. The mode is the measure of central tendency that identifies the most frequently occurring value in a dataset. Unlike the mean or median, the mode directly counts the frequency of each distinct value and returns the value with the highest count, making it the correct choice for this specific requirement.

Answer

Standard deviation

Answer

Median

Answer

Mean

Question 15

An 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?

Accepted Answer

Data mapping and transformation. Data mapping and transformation is the correct technique because the JSON responses from different supplier APIs use inconsistent field naming conventions (e.g., 'product_id' vs. 'ProductID'). This technique defines a schema to map source fields to a standardized target format, ensuring data consistency before loading into the company's system. Without transformation, downstream processes like analytics or inventory management would fail due to mismatched field names.

Answer

Data compression

Answer

Data deduplication

Answer

Data aggregation

Question 16

Which TWO chart types are best suited for visualizing the distribution of a single continuous variable? (Select two.)

Accepted Answer

Box plot. Histogram shows frequency bins; box plot shows quartiles and outliers.

Answer

Scatter plot

Answer

Line chart

Answer

Pie chart

Question 17

A 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?

Accepted Answer

Include a caveat that returns from the last week are missing and revenue may be overstated.. When data has limitations, it's important to disclose them, such as missing returns, to avoid misleading conclusions.

Answer

Delay the report until returns are processed.

Answer

Report the 15% increase as final, because the returns are insignificant.

Answer

State that the revenue increase is exactly 15% and provide a confidence interval.

Question 18

Drag and drop the steps to perform a data audit in the correct order.

Accepted Answer

1. Inventory, 2. Quality Assessment, 3. Compliance Check, 4. Documentation, 5. Recommendations. Data audit begins with inventory, quality assessment, compliance check, documentation, and recommendations.

Answer

1. Quality Assessment, 2. Inventory, 3. Compliance Check, 4. Documentation, 5. Recommendations

Answer

1. Inventory, 2. Compliance Check, 3. Quality Assessment, 4. Documentation, 5. Recommendations

Answer

1. Inventory, 2. Quality Assessment, 3. Documentation, 4. Compliance Check, 5. Recommendations

Question 19

A 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?

Accepted Answer

Acknowledge the discrepancy and explain possible reasons such as changes in data collection methods or patient population. It demonstrates the core competency of 'Communicating Data Insights' by acknowledging the discrepancy between the current finding and previous reports, which builds trust with skeptical stakeholders. By explaining possible reasons such as changes in data collection methods or patient population, the analyst maintains credibility and invites collaborative investigation into data quality issues, rather than dismissing concerns or hiding details.

Answer

Emphasize the statistical significance of the finding and ignore previous reports

Answer

Present the data without any explanation and let them draw conclusions

Answer

Remove the demographic detail to avoid controversy

Question 20

An 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?

Accepted Answer

Scatter plot with a trend line. A scatter plot with a trend line (Option D) is the best choice because it plots each data point individually, allowing the analyst to see the overall relationship between advertising spend and website traffic while the trend line (often a linear regression line) smooths out the influence of outliers. This chart type minimizes the visual impact of extreme values by focusing on the central tendency and direction of the data, making it ideal for identifying trends over 12 months despite promotional event spikes.

Answer

Pie chart

Answer

Bar chart

Answer

Heatmap