PL-300 Visualize and analyze the data Practice Test 4 — 15 Questions

Question 1

You have a Power BI report that uses a live connection to an Azure Analysis Services (AAS) model. Users report that the report takes a long time to load when they apply a slicer on a calculated column. What should you recommend?

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

Accepted Answer

Convert the calculated column to a measure if the logic allows. With a live connection to Azure Analysis Services, calculated columns are evaluated during data processing and stored in the model. When used in a slicer, each selection requires scanning the entire column, leading to slow performance. Converting the calculated column to a measure (if the logic allows) can improve performance because measures are evaluated at query time only for the relevant filter context, reducing computation. Option A is incorrect: replacing with a calculated table would not solve the issue and could increase model size. Option C is incorrect: incremental refresh is a feature for import mode, not for live connections. Option D is incorrect: disabling cross-filtering does not address the performance of the calculated column itself.

Answer

Replace the calculated column with a calculated table

Answer

Implement incremental refresh on the calculated column

Answer

Disable cross-filtering between the slicer and the visual

Question 2

You are designing a Power BI report for a sales team. The team needs to see revenue by product category, but also want to view daily trends for a selected product. The data has over 10 million rows. What visual design approach minimizes report load time?

Accepted Answer

Create a drillthrough page with a line chart showing daily revenue, and use category page as source. Using a drillthrough page with a single visual reduces initial load because the detail visual only loads when the user drills through. This minimizes the amount of data rendered on the main report page, improving performance for large datasets.

Answer

Use a custom visual that combines both views in one chart

Answer

Use bookmarks to switch between category view and daily trend view

Answer

Place a stacked column chart showing all categories and a line chart for trend on the same page

Question 3

You want to create a measure that calculates the percentage of total sales for each product category. What DAX function should you use to get the grand total?

Accepted Answer

ALL. ALL removes all filters from a table or column, returning a full table or column without any filters. This is essential for calculating a grand total (e.g., sum of all sales) that ignores any slicers or report filters, allowing you to compute percentage of total by dividing the filtered measure by the result of the measure that uses ALL. Option D is correct. Option A (VALUES) returns distinct values from a column, not the unfiltered total. Option B (ALLSELECTED) respects user filter selections from slicers, so it doesn't give the grand total if slicers are applied. Option C (REMOVEFILTERS) is similar to ALL but typically used to remove filters from specific columns; however, ALL is the standard for grand total calculations.

Answer

VALUES

Answer

ALLSELECTED

Answer

REMOVEFILTERS

Question 4

You have a Power BI report that uses Import mode. The dataset is refreshed daily. Users are complaining that the report shows data from yesterday morning even though the refresh completed successfully at 2:00 AM today. What should you check first?

Accepted Answer

Examine the incremental refresh policy's rangeStart and rangeEnd parameters. The dataset might be using incremental refresh with rangeStart and rangeEnd parameters that exclude the most recent data. Since the refresh completes successfully, the issue is not a failure but a filtering problem. Examining these parameters is the first troubleshooting step. Option A (RLS) only controls data visibility per user, not freshness. Option B: The refresh history shows success, so no errors. Option C: The gateway is not the issue because the refresh succeeded; gateway problems would cause failure.

Answer

Check row-level security (RLS) role assignments

Answer

Check the refresh history for errors

Answer

Verify the on-premises data gateway is running

Question 5

You have a Power BI semantic model with a date table that has a 1:* relationship to a Sales table. You need to create a measure that shows the number of sales transactions for the last 30 days. The date table is marked as a date table. Which DAX expression should you use?

Accepted Answer

CALCULATE(COUNTROWS(Sales), DATESINPERIOD('Date'[Date], MAX('Date'[Date]), -30, DAY)). DATESINPERIOD returns a set of dates from the last date in the current filter context back 30 days. Option A (DATESINPERIOD) is correct. Option B (DATESBETWEEN with TODAY) fails because TODAY is not dynamic to the filter context—it always references the current date, not the last date in the selected period. Option C (PREVIOUSMONTH) returns the entire previous month, not a rolling 30-day window. Option D (DATEADD) shifts dates by -30 days but does not guarantee a contiguous 30-day period from the last date; it returns the same number of dates shifted, which may not be 30 consecutive days.

Answer

CALCULATE(COUNTROWS(Sales), DATESBETWEEN('Date'[Date], TODAY()-30, TODAY()))

Answer

CALCULATE(COUNTROWS(Sales), PREVIOUSMONTH('Date'[Date]))

Answer

CALCULATE(COUNTROWS(Sales), DATEADD('Date'[Date], -30, DAY))

Question 6

You need to create a Power BI report that shows sales by region and by product category. Users should be able to click on a region and see the sales for that region across all product categories. What is the best way to enable this?

Accepted Answer

Enable cross-filtering between the region slicer and the category chart. Cross-filtering is the simplest method. Option B is correct. Option A is wrong because drillthrough navigates to a detail page. Option C is wrong because tooltips don't change the visual. Option D is wrong because bookmarks require manual setup.

Answer

Set up a drillthrough page that filters by region

Answer

Use a report page tooltip to show category details

Answer

Create a bookmark for each region

Question 7

Which TWO of the following are valid ways to create a date table in Power BI? (Select two.)

Accepted Answer

Using DAX: DateTable = CALENDARAUTO(). The correct answers are B and D. B is correct because CALENDARAUTO() returns a table of dates automatically based on the data model, making it a valid way to create a date table. D is correct because you can generate a list of dates in Power Query from a start to end date. A is wrong because DATESYTD returns only dates in a year-to-date period, not a full date table. C is wrong because CALCULATE is not a table constructor; it evaluates an expression in a modified filter context. E is wrong because SUMMARIZE returns a summary table over existing columns, not a standalone date table.

Answer

Using DAX: DateTable = DATESYTD('Date'[Date])

Answer

Using DAX: DateTable = CALCULATE(DISTINCT(Sales[Date]))

Answer

Using DAX: DateTable = SUMMARIZE(Sales, Sales[Date])

Question 8

Which THREE of the following are best practices when designing Power BI reports for mobile devices? (Select three.)

Accepted Answer

Create a dedicated mobile layout view. Power BI provides a dedicated mobile layout view that allows you to optimize report pages specifically for mobile devices. By using this view, you can rearrange, resize, and hide visuals to ensure they display properly on smaller screens, which is a best practice for mobile report design.

Answer

Use custom visuals for advanced analytics

Answer

Include multiple slicers for flexible filtering

Question 9

Which TWO of the following are true about using AI visuals in Power BI? (Select two.)

Accepted Answer

The Q&A visual allows users to type natural language questions. The Q&A visual allows users to type natural language questions and get answers in the form of visuals. Option E is correct: The Key Influencers visual uses machine learning to identify factors that affect a metric. Option A is wrong: The Copilot feature is not available in all Power BI licenses; it requires a Premium capacity or Fabric capacity license. Option B is wrong: The Key Influencers visual is an AI visual that relies on machine learning, not a native visual without AI. Option C is wrong: Smart Narratives is a built-in AI visual, not a custom visual from AppSource.

Answer

The Copilot feature is available in all Power BI licenses

Answer

The Key Influencers visual is a native visual available without AI

Answer

Smart Narratives is a custom visual from AppSource

Question 10

Which THREE of the following are valid considerations for choosing between Import and DirectQuery storage modes? (Select three.)

Accepted Answer

Import mode provides faster query performance for aggregated data. Import mode stores data in memory, enabling fast query performance for aggregated data. Option C is correct because Import mode has size limits (e.g., 1 GB per dataset in shared capacity) that depend on the Power BI capacity. Option E is correct because DirectQuery queries the source directly, making it suitable for scenarios that require real-time data. Option B is incorrect because DirectQuery does not support all DAX functions; for example, many time intelligence functions are limited or require specific conditions. Option D is incorrect because DirectQuery can query large data sources; in fact, it is often used for very large datasets that cannot be fully imported.

Answer

DirectQuery mode supports all DAX functions without limitations

Answer

DirectQuery mode cannot query large data sources

Question 11

You have a Power BI report that uses a composite model with both Import and DirectQuery sources. You need to ensure that a measure using SUMX performs well. What should you do?

Accepted Answer

Create a calculated column in the source system to pre-aggregate values. In a composite model with both Import and DirectQuery sources, using SUMX to iterate over a DirectQuery table can be slow because each row may trigger a query. Option C recommends creating a calculated column in the source system (such as a computed column in SQL) that stores pre-aggregated values. This moves the aggregation closer to the data source, reducing the iteration overhead in Power BI. For example, you could add a column to a dimension table that contains the sum of related transaction rows, so that the measure can simply reference that column instead of looping over the fact table. Options A and B are incorrect: disabling relationships breaks the model, and using CALCULATE does not address iteration. Option D is incorrect because replacing SUMX with SUM changes the calculation logic and may not yield the same result.

Answer

Disable relationships between tables

Answer

Use CALCULATE instead of SUMX

Answer

Replace SUMX with SUM and adjust the model

Question 12

You have a Power BI report that shows sales by region. The map visual displays regions with incorrect boundaries. What is the most likely cause?

Accepted Answer

Bing Maps geocoding inaccuracies.. Power BI map visuals rely on Bing Maps for geocoding, and inaccuracies in Bing Maps data can cause incorrect region boundaries. Option A is incorrect because the map visual is commonly used for geographic data and is not the source of boundary issues. Option B is incorrect because data refresh affects data values, not the underlying map boundaries. Option C is incorrect because overlapping labels are a display issue unrelated to boundary accuracy.

Answer

The map visual is not the best choice for the data.

Answer

The data source is not refreshed.

Answer

The map labels are overlapping.

Question 13

You need to create a measure that calculates the year-over-year growth of sales. Which DAX function should you use?

Accepted Answer

SAMEPERIODLASTYEAR. SAMEPERIODLASTYEAR (option B) returns the same period in the previous year, making it ideal for year-over-year growth calculations. DATEADD (option A) can shift by any interval but is not specifically designed for direct YoY comparison. PARALLELPERIOD (option C) shifts by a full period (e.g., full month), which may not align with the exact same days. PREVIOUSYEAR (option D) returns the entire previous year, not the corresponding period.

Answer

DATEADD

Answer

PARALLELPERIOD

Answer

PREVIOUSYEAR

Question 14

You are designing a report for executives. They need to see both high-level KPIs and the ability to drill down into details. Which approach should you recommend?

Accepted Answer

Use drillthrough pages to navigate from summary visuals to detail pages.. Drillthrough pages allow users to click on a high-level visual and see detailed data for that specific context, providing both a KPI summary and drill-down capability. Option A is incorrect because a single table visual with drill-down does not present high-level KPIs effectively. Option C is less optimal because bookmarks switch entire views rather than providing context-sensitive navigation from a visual. Option D is incorrect because tooltips show only limited details, not a full drilldown experience.

Answer

Place all data in a single table visual with drill-down capability.

Answer

Use bookmarks to switch between summary and detail views.

Answer

Use report page tooltips to show details on hover.

Question 15

You need to ensure that a Power BI report is accessible to users with visual impairments. Which feature should you configure?

Accepted Answer

Add alt text to each visual.. Power BI allows adding alt text to visuals, which screen readers can read, making the report accessible to users with visual impairments. Option A is incorrect because applying a high-contrast theme only adjusts colors for readability but does not provide textual descriptions for screen readers. Option B is incorrect because enabling data labels adds numeric values but does not provide descriptive text that screen readers can interpret. Option D is incorrect because custom tab order aids keyboard navigation but does not address visual impairments directly.

Answer

Apply a high-contrast theme.

Answer

Enable data labels on all visuals.

Answer

Set custom tab order for visuals.