PL-300 Visualize and analyze the data Practice Test 9 — 15 Questions

Question 1

Refer to the exhibit. The DAX measure is intended to return the previous purchase amount for the same customer. However, it returns the current row's amount for most rows. What is the most likely reason?

Accepted Answer

The variable PreviousDate is evaluated within the current filter context, which may be the same as LastDate for single rows. Option B is correct because the variable PreviousDate is evaluated in the filter context of the current row, causing it to return the same date as LastDate when there is only one row per customer per date. Option A is wrong because ALLEXCEPT retains the CustomerID filter, which is correct. Option C is wrong because the measure uses CALCULATE correctly. Option D is wrong because the data type is not the issue.

Answer

The data type of OrderDate is text, causing comparison issues

Answer

ALLEXCEPT removes all filters except CustomerID, so the measure cannot find the previous date

Answer

The CALCULATE function does not support the 'Sales'[OrderDate] = PreviousDate syntax

Question 2

You have a Power BI report with a matrix visual showing sales by year and quarter. Users want to drill down from year to quarter and expand back up. Which feature should you enable?

Accepted Answer

Enable drill-down mode and add a hierarchy of Year and Quarter. Option A is correct because the drill-down mode in a matrix visual allows hierarchical navigation. Option B is wrong because bookmarks do not provide interactive drill-down. Option C is wrong because the drill-through feature navigates to a different page. Option D is wrong because tooltips do not enable drill-down.

Answer

Set up drill-through pages for each quarter

Answer

Create bookmarks for each level

Answer

Add a tooltip page showing quarterly details

Question 3

You need to create a measure that calculates the year-over-year growth percentage for sales. Which DAX function combination is most appropriate?

Accepted Answer

CALCULATE with SAMEPERIODLASTYEAR and DIVIDE. Option C is correct because CALCULATE with SAMEPERIODLASTYEAR calculates the previous year's sales, and the DIVIDE function handles division safely. Option A is wrong because TOTALYTD is for year-to-date, not year-over-year. Option B is wrong because DATEADD is used but not with SAMEPERIODLASTYEAR. Option D is wrong because PREVIOUSMONTH is for month-over-month.

Answer

CALCULATE with DATEADD and SUM

Answer

TOTALYTD and DIVIDE

Answer

PREVIOUSMONTH and SUM

Question 4

You are troubleshooting a Power BI DirectQuery model that connects to a SQL Server database. A slicer on 'Region' is slow to respond. The region column has 50 distinct values. What is the best optimization?

Accepted Answer

Create an index on the Region column in the source database. Option D is correct because in DirectQuery mode, queries are sent to the source; creating an index on the region column will speed up filtering. Option A is wrong because Import mode is not always feasible or desired. Option B is wrong because increasing cache size does not help DirectQuery. Option C is wrong because reducing cardinality would lose information.

Answer

Increase the cache size in Power BI Desktop

Answer

Switch the model to Import mode

Answer

Reduce the number of distinct values in Region

Question 5

A user wants to see the top 10 products by sales but also include a total row at the bottom of the table. How can you achieve this?

Accepted Answer

Enable the total row in the formatting pane of the table visual. Option B is correct because the 'Show items with no data' option is unrelated, and a total row can be enabled in the formatting pane for table visuals. Option A is wrong because the total row is not a built-in feature for all visuals; it is available in table/matrix visuals. Option C is wrong because the 'Top N' filter does not include a total row. Option D is wrong because a calculated column is not needed.

Answer

Apply a Top N filter to the visual and add a measure for total

Answer

Use the 'Show items with no data' option

Answer

Create a separate card visual for total sales

Question 6

You create a bar chart showing sales by product category. You want to sort the categories by total sales descending. What should you do?

Accepted Answer

Click the ellipsis menu on the visual and choose 'Sort by Sales' then 'Sort descending'. Option A is correct because you can sort the visual by the Sales field in descending order. Option B is wrong because sorting by category name is alphabetical. Option C is wrong because the data model does not have a sort by column for this purpose. Option D is wrong because sorting by a measure is done via the visual's sort options.

Answer

Sort the visual by category name ascending

Answer

Create a measure that returns the sales value and sort by that measure

Answer

In the data model, set the Sort by Column property for Category

Question 7

Which TWO actions can improve the performance of a Power BI report that uses DirectQuery? (Select two.)

Accepted Answer

Set up aggregations in the data source. Options B and C are correct because reducing the number of visuals reduces queries, and setting up aggregations reduces the data scanned. Option A is wrong because increasing cache size does not affect DirectQuery. Option D is wrong because using calculated columns moves computation to Power BI, but they are evaluated row by row and can be slow. Option E is wrong because using many small visuals increases queries.

Answer

Use calculated columns instead of measures

Answer

Add more slicers to allow users to filter data

Answer

Increase the cache size in the Power BI service

Question 8

Which THREE factors should you consider when designing a Power BI data model for a star schema? (Select three.)

Accepted Answer

Fact tables should contain numeric measures and foreign keys. Option B is correct because fact tables in a star schema store numeric, aggregatable measures (e.g., sales amount, quantity) and foreign keys that reference dimension tables. This structure enables efficient summarization and slicing by dimensions, which is a core requirement for Power BI performance and DAX calculations.

Answer

Use many-to-many relationships between dimensions

Answer

Dimension tables should be normalized to reduce redundancy

Question 9

Which TWO Power BI visuals can be used to display hierarchical data? (Select two.)

Accepted Answer

Decomposition tree. The Decomposition tree (C) is correct because it is a Power BI custom visual designed specifically for hierarchical data, allowing users to drill down into dimensions interactively. The Matrix (D) is correct because it supports hierarchical row and column headers, enabling multi-level grouping and expansion of data.

Answer

Scatter plot

Answer

Card

Answer

Pie chart

Question 10

Refer to the exhibit. The DAX query is executed in DAX Studio. It returns a table with Category and Total Sales. However, the total sales values are incorrect because they include all categories regardless of context. What is the most likely issue?

Accepted Answer

The query does not filter by any specific context, so it returns grand total for each category. Option C is correct because SUMMARIZE does not automatically apply filter context from the report; it evaluates in the current filter context of the query. Option A is wrong because the relationship exists. Option B is wrong because the syntax is valid. Option D is wrong because the grouping is correct.

Answer

The SUMMARIZE function syntax is incorrect

Answer

The relationship between Sales and Product is inactive

Answer

The GROUP BY column should be from the Sales table

Question 11

Refer to the exhibit. This JSON defines a row-level security (RLS) role in Power BI. A user assigned to the 'Sales Manager' role runs a report that shows total sales across all regions. The sum displayed is lower than expected. What is the most likely reason?

Accepted Answer

The RLS filter restricts data to the West region only. Option B is correct because the RLS role filters the Sales table to only show rows where Region is 'West', so the total sum only includes West region sales. Option A is wrong because the filter is applied regardless of the role's name. Option C is wrong because the sum is not a bug; it's the intended behavior. Option D is wrong because the user is in the role, so RLS is enforced.

Answer

The role name 'Sales Manager' does not match the user's job title

Answer

The user is not a member of the role

Answer

The FILTER function syntax is incorrect and causes an error

Question 12

You are a Power BI analyst at a retail company. The company has a SQL Server data warehouse with tables: 'Sales' (SalesID, ProductID, CustomerID, SalesDate, Amount, Quantity), 'Products' (ProductID, ProductName, Category, UnitPrice), 'Customers' (CustomerID, CustomerName, Region, Segment). The data warehouse is refreshed nightly. You need to build a Power BI solution that meets the following requirements:
- The report must be published to the Power BI service and support scheduled refresh.
- Users must be able to analyze sales by product category and customer region.
- The data model should follow a star schema design.
- A measure must calculate the running total of sales by date.
- The report must include a visual that shows the top 5 products by sales amount for the current year.
- Performance is critical; the report should load quickly.

You have imported the data into Power BI Desktop. Which of the following actions should you take to meet the requirements?

Accepted Answer

Create a date dimension table. Build a star schema with Sales as fact and Products, Customers, and Date as dimensions. Use TOTALYTD for running total and TOPN for top products.. Option B is correct because creating a date dimension, using a star schema, and using DAX measures (including TOTALYTD for running total and TOPN for top products) is the best practice. Option A is wrong because using a single flat table would create a poor model and slow performance. Option C is wrong because DirectQuery would be slower for aggregated measures like running total. Option D is wrong because using calculated columns for running total is less efficient than measures.

Answer

Import all tables. Create a calculated column for running total using FILTER and EARLIER. Use a slicer to filter by current year and sort a bar chart by sales.

Answer

Use DirectQuery mode to connect to the data warehouse. Write a SQL query for each visual to ensure real-time data. Use a SQL window function for running total.

Answer

Create a single flat table by merging all tables in Power Query. Use a measure for running total with EARLIER function. Create a Top N filter on a table visual.

Question 13

You need to design a report that allows users to drill from a yearly sales summary to quarterly details, then to monthly details, while maintaining the ability to go back. Which visual interaction should you enable?

Accepted Answer

Drill-down. Option B is correct because drill-down is the built-in Power BI feature that allows users to drill into hierarchical levels and use the back button to navigate up. Option A is wrong because drillthrough navigates to a separate page, not drill within the same visual hierarchy. Option C is wrong because tooltips provide additional detail on hover, not drill-down. Option D is wrong because bookmarks capture a specific state, not hierarchical drill.

Answer

Bookmarks

Answer

Tooltips

Answer

Drillthrough

Question 14

You have a report page that shows sales by region. You want users to be able to select a region and see the corresponding sales details on the same page without navigating away. Which feature should you use?

Accepted Answer

Slicer. Option A is correct because a slicer filters the entire page based on the selected value, showing details on the same page. Option B is wrong because drillthrough navigates to a different page. Option C is wrong because a card visual only shows a single value. Option D is wrong because a matrix with expand/collapse is for hierarchical display, not cross-filtering.

Answer

Drillthrough

Answer

Matrix with expand/collapse

Answer

Card visual

Question 15

You are building a report that uses a calculated column with the formula: 'Profit = Sales[Revenue] - Sales[Cost]'. Users report that the Profit column shows negative values for some rows when it should be positive due to a known data issue in the Cost column. What is the best approach to handle this without modifying the source data?

Accepted Answer

Modify the calculated column to use COALESCE or IF to treat missing or incorrect cost values.. Option C is correct because using Data Analysis Expressions (DAX) functions like IF or COALESCE allows you to handle data quality issues within the model. Option A is wrong because it uses DirectQuery, but the issue is in the model, not the query type. Option B is wrong because conditional formatting only changes visual appearance, not the underlying value. Option D is wrong because removing negative values would hide the issue without fixing it.

Answer

Create a measure that filters out rows with negative profit.

Answer

Apply conditional formatting on the Profit column to hide negative values.

Answer

Switch the table to DirectQuery mode to retrieve live data.

PL-300 Visualize and analyze the data Practice Test 9 — 15 Questions

Exhibit

PL-300 Visualize and analyze the data Practice Test 9 — 15 Questions

Exhibit