DA0-001 Practice Test 19 — 15 Questions

Question 1

A 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?

Accepted Answer

Use a discrete color scale with distinct bins for sales ranges.. Option D is correct because a discrete color scale with distinct bins for sales ranges eliminates the ambiguity caused by a continuous gradient, where moderate sales values blend together. By grouping sales into defined intervals (e.g., $0–$10K, $10K–$50K, etc.), each region is assigned a unique, easily distinguishable color, making it immediately clear which sales bracket a region falls into without requiring precise color differentiation.

Answer

Switch to a diverging color scheme with a neutral midpoint.

Answer

Increase the map size to show more detail.

Answer

Add data labels to each region showing exact sales numbers.

Question 2

A 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.)

Accepted Answer

Provide a detailed appendix for technical staff.. Option B is correct because a detailed appendix allows technical staff to access granular data, methodology, and supporting statistics without overwhelming the executive audience. This practice aligns with the principle of audience segmentation in data communication, ensuring that each stakeholder group receives the appropriate level of detail without disrupting the presentation flow.

Answer

Use only text-heavy slides to include all details.

Answer

Avoid any data visualizations to prevent confusion.

Answer

Use complex statistical terms without explanation.

Question 3

A 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?

Accepted Answer

Use a bullet chart showing actual vs. target.. A bullet chart is the most effective method because it is specifically designed to show performance against a target, combining a bar for the actual value ($1.2M) with a reference line or marker for the target ($1.33M). This allows the analyst to immediately visualize the 10% shortfall in a compact, high-density format without needing to compare separate numbers or interpret a trend. It directly addresses the goal of highlighting the variance, which is a core principle in data presentation for performance dashboards.

Answer

Show a trend line of the last 12 months.

Answer

Provide a table of all monthly targets and actuals.

Answer

Display the actual revenue only.

Question 4

Refer to the exhibit. A data analyst is reviewing the job log. Which of the following best explains the reduction in record count?

Accepted Answer

The job aggregated data by region and date, reducing granularity.. Option B is correct because the job aggregated data by region and date, reducing granularity from transactional to summary level. The null exclusion of 50 records is minor. A is incorrect as the job completed successfully; C is incorrect because only 50 records were excluded; D is incorrect as no filter is mentioned.

Answer

The null region exclusion caused the reduction.

Answer

The job applied a filter to only include top regions.

Answer

The job failed to process half the data.

Question 5

An analyst is presenting findings to stakeholders. Which TWO techniques effectively communicate uncertainty in data? (Choose TWO.)

Accepted Answer

Include confidence intervals.. Confidence intervals provide a range of values that likely contain the true population parameter, offering a clear measure of uncertainty around a point estimate. This technique is fundamental in inferential statistics and directly communicates the precision of the data, helping stakeholders understand the reliability of the findings.

Answer

Use only point estimates.

Answer

Remove all outliers from the data.

Answer

State exact numbers without ranges.

Question 6

Refer to the exhibit. A data analyst receives this error when running a data load script. What is the most likely cause?

Accepted Answer

The customer_id 12345 already exists in the table. Option B is correct. The error message explicitly states 'Duplicate entry '12345' for key 'PRIMARY'', meaning a record with customer_id 12345 already exists in the table. Option A (email too long) would give a different error. Option C (null name) would not cause primary key violation. Option D (connection lost) would give a different error.

Answer

The email field is too long

Answer

The database connection is lost

Answer

The name field is null

Question 7

A 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?

Accepted Answer

Use a simple annotated line chart with a clear callout on the decline.. Option D is correct because a simple annotated line chart with a clear callout on the decline is intuitive and draws attention to the key insight. Options A, B, and C are either too complex or not focused.

Answer

Include a complex statistical model showing the correlation.

Answer

Show a scatter plot of wait time vs. satisfaction.

Answer

Provide raw data in a spreadsheet for review.

Question 8

A 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?

Accepted Answer

The filter context is inadvertently excluding some regions.. Option D is correct because filter context can inadvertently exclude certain regions, leading to incorrect totals. Options A, B, and C are less likely: A affects performance not accuracy; B would be caught by correct queries; C could cause aggregation differences but filters are a common issue.

Answer

The visualizations are using a different aggregation level.

Answer

The data model includes duplicate records.

Answer

The dashboard is using a live connection instead of an extract.

Question 9

A data analyst is preparing a data storytelling presentation for a non-technical audience. Which THREE techniques are most effective for communicating insights?

Accepted Answer

Using relevant visuals such as charts and graphs.. Option A is correct because data storytelling for non-technical audiences relies on visuals like charts and graphs to make complex data patterns immediately understandable, reducing cognitive load and enabling faster insight absorption. Effective visuals should be simple, clearly labeled, and directly tied to the narrative, avoiding clutter that could confuse the audience.

Answer

Including raw data tables for reference.

Answer

Adding complex statistical terms to demonstrate expertise.

Question 10

A 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?

Accepted Answer

Use a simple bar chart comparing readmission rates by condition.. Option C is correct because a simple bar chart directly compares readmission rates across chronic conditions using a visual format that is intuitive for an audience with limited data literacy. It avoids overwhelming them with raw numbers or complex statistical outputs, enabling quick comprehension and fostering discussion on actionable preventive measures within the 15-minute timeframe.

Answer

Present a table of raw numbers for each condition.

Answer

Show a complex regression model output to demonstrate correlation.

Answer

Show a scatter plot of age vs. readmission rate.

Question 11

A data analyst is tasked with presenting the results of a customer churn analysis to a group of marketing managers. The model identified that customers with low engagement scores are 3 times more likely to churn. The analyst wants to effectively communicate this finding to persuade the managers to focus on engagement. Which of the following is the most compelling way to present this insight?

Accepted Answer

Calculate the potential revenue increase if engagement improves by 10%. Option A is correct because translating the finding into potential revenue impact resonates with managers' business goals. Option B (bar chart) is factual but less persuasive. Option C (scatter plot) is not compelling. Option D (table) is less engaging.

Answer

Show a table with raw churn rates by engagement score

Answer

Use a bar chart comparing churn rates of low vs. high engagement

Answer

Show a scatter plot of engagement score vs. churn

Question 12

A 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?

Accepted Answer

Include an interactive dashboard with filters by region.. Option B is correct because interactive dashboards with filters allow the board to see high-level summaries while drilling into region-specific details on demand. This approach aligns with modern BI tools like Tableau or Power BI, which support dynamic filtering and cross-filtering without requiring separate report pages.

Answer

Use a single summary metric for all regions.

Answer

Embed a table of data for each region in an appendix.

Answer

Provide a static executive summary with no drill-down.

Question 13

A data analyst creates a dashboard for executives that shows a key metric trending downward. The analyst notices that the metric is highly volatile day-to-day. Which visualization type is most appropriate to show the underlying trend?

Accepted Answer

7-day moving average line chart.. Option C is correct because a moving average line chart smooths out daily volatility to reveal the trend. A daily bar chart shows noise; a pie chart is inappropriate for trends; a scatter plot with regression line could show correlation but not trend over time as clearly.

Answer

Pie chart showing proportion of days.

Answer

Scatter plot with regression line.

Answer

Daily bar chart.

Question 14

After 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?

Accepted Answer

Provide a detailed written report with charts and explanations.. Option C is correct because a detailed written report with charts and explanations allows stakeholders to review at their own pace and provides depth. Option A is wrong because creating a new dashboard for every request is inefficient. Option B is wrong because raw data files lack context and interpretation. Option D is wrong because holding another meeting delays information.

Answer

Create a new dashboard with all the data.

Answer

Send the raw data file to the stakeholders.

Answer

Hold another meeting to verbally explain the trend.

Question 15

A 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?

Accepted Answer

$.customers[*].email. Option C is correct because the JSONPath expression `$.customers[*].email` uses the wildcard `[*]` to select all elements in the `customers` array and then accesses the `email` property of each element. This matches the requirement to extract email addresses for all customers from the JSON snippet.

Answer

$.customers[0].email

Answer

$..email

Answer

$.customers.email