DA0-002 Practice Test 43 — 15 Questions

Question 1

A 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?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

SAMEPERIODLASTYEAR. SAMEPERIODLASTYEAR returns a set of dates in the previous year for the same period, which is ideal for year-over-year comparisons.

Answer

PREVIOUSYEAR

Answer

TOTALYTD

Answer

DATEADD

Question 2

A data analyst is creating a dashboard for a sales team. Which TWO actions adhere to dashboard design best practices?

Accepted Answer

Using consistent color coding across charts. Using consistent color coding and placing the most important metric prominently are best practices. Using many bright colors and 3D effects are not.

Answer

Including 3D effects to make charts look more professional

Answer

Adding detailed axis labels and titles to every chart

Answer

Using as many bright colors as possible to make the dashboard attractive

Question 3

A 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?

Accepted Answer

Visual hierarchy. Visual hierarchy ensures that the most important metrics (like underperforming regions) are prominently displayed, drawing the user's attention first.

Answer

Data-ink ratio

Answer

Appropriate precision

Answer

Consistent color coding

Question 4

Drag and drop the steps to conduct a hypothesis test in the correct order.

Accepted Answer

State hypotheses, Set significance level (alpha), Collect data, Compute test statistic, Make decision. Hypothesis testing involves stating hypotheses, setting alpha, collecting data, computing test statistic, and making a decision.

Answer

Collect data, State hypotheses, Set significance level (alpha), Compute test statistic, Make decision

Answer

State hypotheses, Set significance level (alpha), Compute test statistic, Collect data, Make decision

Answer

State hypotheses, Collect data, Set significance level (alpha), Compute test statistic, Make decision

Question 5

Refer to the exhibit. Which type of ensemble method is being used?

Accepted Answer

Bagging. The exhibit shows multiple base models (Model 1, Model 2, Model 3) trained in parallel on bootstrap samples of the data, and their predictions are combined via averaging (regression) or majority voting (classification). This parallel training with resampled data and equal-weight aggregation is the defining characteristic of bagging (Bootstrap Aggregating).

Answer

Boosting

Answer

Stacking

Answer

Voting

Question 6

A healthcare analyst is creating a report on patient outcomes. To comply with privacy regulations, which action should be taken before publishing?

Accepted Answer

Anonymize personally identifiable information. Anonymizing PII protects patient identities and ensures compliance with privacy laws like HIPAA.

Answer

Include patient names for context

Answer

Provide raw data to all stakeholders

Answer

Aggregate data without anonymization

Question 7

A 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.)

Accepted Answer

Box plot. Histograms show distribution of a continuous variable, and box plots show distribution with quartiles and outliers. Pie charts and bar charts are not for distribution.

Answer

Pie chart

Answer

Bar chart

Answer

Line chart

Question 8

A 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?

Accepted Answer

"Overstocking occurs in 30% of warehouses. This indicates poor demand forecasting. We recommend implementing a just-in-time system to reduce inventory holding costs by 15%.". A proper data-driven recommendation follows the sequence: evidence → insight → recommendation → expected impact.

Answer

"Implement a just-in-time system."

Answer

"Our inventory costs are too high. We need to fix this."

Answer

"We should reduce inventory by 20%. This will save costs."

Question 9

A data warehouse team is considering moving from an ETL to an ELT approach. Which THREE of the following are advantages of ELT over ETL?

Accepted Answer

Reduces data loading time because transformations are done after loading. In ELT, data is loaded into the data warehouse first and transformations are applied afterward. This reduces the initial loading time since no transformation processing occurs during the load phase, allowing raw data to be ingested more quickly.

Answer

Requires less storage space in the data warehouse

Answer

Ensures data is cleaned before loading

Question 10

A 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?

Accepted Answer

TRIM. TRIM removes leading and trailing spaces from a string.

Answer

LTRIM

Answer

REPLACE

Answer

SUBSTRING

Question 11

A 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?

Accepted Answer

A dual-axis chart with bars for actual and budget by month for each department, and a line for variance. A dual-axis chart with bars for actual and budget by month for each department, and a line for variance, allows the CFO to quickly compare actual vs budget figures and see the trend of variance over time. Option B (waterfall chart) is better suited for cumulative changes over time, not month-by-month comparisons. Option C (table with conditional formatting) does not provide a quick visual overview of trends. Option D (stacked bar chart) makes it difficult to compare actual vs budget across departments and months, and obscures individual department trends.

Answer

A waterfall chart showing cumulative variance over the year

Answer

A table with conditional formatting to highlight over-budget cells

Answer

Stacked bar chart with one bar per month, segments showing each department's actual and budget

Question 12

Which TWO actions are best practices for creating effective data visualizations?

Accepted Answer

Avoid using more than five slices in a pie chart. Pie charts with more than five slices become cluttered and difficult to read, making it hard for viewers to compare proportions accurately. Limiting slices to five or fewer ensures the chart remains clear and effectively communicates the relative sizes of categories. This best practice aligns with data visualization principles that prioritize clarity and cognitive ease.

Answer

Maximize data-ink ratio by removing all whitespace

Answer

Always include gridlines with high contrast

Answer

Use 3D effects to make charts look professional

Question 13

Refer 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?

Accepted Answer

The query contains a syntax mistake.. The error log explicitly states 'repeated SQL syntax errors,' which directly indicates that the SQL query being executed is malformed. A syntax mistake in the query (e.g., missing keyword, incorrect clause order, or mismatched parentheses) will cause the database to reject the statement before any execution begins, leading to the exact error described.

Answer

The database server is offline.

Answer

The user does not have permissions to access the table.

Answer

The network connection timed out.

Question 14

A 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?

Accepted Answer

Stratified sampling. Stratified sampling ensures proportional representation of subgroups (strata).

Answer

Cluster sampling

Answer

Simple random sampling

Answer

Systematic sampling

Question 15

A 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?

Accepted Answer

json_normalize(). `json_normalize()` is a function in the pandas library specifically designed to flatten semi-structured JSON data (including nested lists and dictionaries) into a tabular DataFrame. This makes it the ideal tool for converting API responses with complex nesting into rows and columns for analysis, unlike simpler JSON parsing functions.

Answer

json.loads()

Answer

to_csv()

Answer

read_json()