PL-300 Practice Test 29 — 15 Questions

Question 1

You are preparing data for a Power BI report. The source data contains a column with mixed data types: some values are numbers, others are text. When loading into Power Query, the entire column is typed as text. What is the likely cause?

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

Accepted Answer

Power Query detected that the column contains text values in some rows, so it set the data type to text. Power Query's column type detection logic examines the entire column during import. If any row contains a non-numeric value (e.g., text), Power Query defaults the entire column to text to avoid data loss or conversion errors. This is the standard behavior when mixed data types are present, regardless of the source format.

Answer

The column was imported as text because the data source is a CSV file

Answer

The 'Detect data type' option was disabled in Power Query settings

Answer

The source data is stored as text in the database

Question 2

You have a table with a column 'FullName' that contains names in the format 'Last, First'. You need to split this column into 'LastName' and 'FirstName' columns. Which Power Query transformation should you use?

Accepted Answer

Split Column by Delimiter using comma.. The 'Split Column by Delimiter' transformation in Power Query is specifically designed to divide a single text column into multiple columns based on a specified delimiter, such as a comma. In this case, the 'FullName' column contains names in the 'Last, First' format, so splitting by a comma delimiter will correctly separate the last name and first name into two distinct columns.

Answer

Pivot the FullName column.

Answer

Group By the FullName column and aggregate.

Answer

Extract first characters using 'Extract' transformation.

Question 3

Which TWO of the following are valid reasons to use a calculated column instead of a measure in Power BI? (Select exactly two.)

Accepted Answer

You need to use the column in a relationship.. Calculated columns are evaluated row by row and stored in the model, making them available for use in relationships. Measures, in contrast, are evaluated at query time and cannot be used to define relationships between tables in Power BI.

Answer

You need to create a hierarchy for drill-down.

Answer

You need to perform a dynamic aggregation that changes with filters.

Answer

You need to calculate a running total.

Question 4

Your organization uses Microsoft Defender for Cloud Apps to monitor Power BI activity. You need to receive an alert when a user exports a report with a sensitivity label of 'Highly Confidential' from Power BI service. What should you configure?

Accepted Answer

Create an activity policy in Microsoft Defender for Cloud Apps.. The correct option is D: create an activity policy in Microsoft Defender for Cloud Apps. Defender for Cloud Apps connects to Power BI via the app connector and its activity policies can trigger alerts on specific user activities, such as downloading or exporting a report, filtered by the sensitivity label 'Highly Confidential'. Option A is wrong because Microsoft 365 compliance alerts do not natively target Power BI report export events with sensitivity-label conditions. Option B is wrong because Power BI audit logging plus Microsoft Sentinel requires custom analytics rules and does not directly provide the built-in activity-policy alerting for this scenario. Option C is wrong because a Microsoft Purview protection policy blocks export rather than generating the requested alert.

Answer

Set up a Microsoft 365 compliance alert for data export events.

Answer

Enable audit logging in Power BI and configure alerts in Microsoft Sentinel.

Answer

Apply a protection policy in Microsoft Purview that blocks export for 'Highly Confidential' labels.

Question 5

Refer to the exhibit. You have a DAX measure that calculates year-over-year sales growth. When you add this measure to a table visual with Year and Month, some rows show blank values. What is the most likely cause?

Accepted Answer

The Calendar table does not have a continuous date range, causing SAMEPERIODLASTYEAR to return blank for some months. The correct answer is D: the Calendar table does not have a continuous date range, causing SAMEPERIODLASTYEAR to return blank for some months. Time-intelligence functions like SAMEPERIODLASTYEAR require a contiguous, gap-free date column in a marked Date table; if any dates are missing, the shifted period lookup fails and the measure returns BLANK for the affected rows. Option A is wrong because SAMEPERIODLASTYEAR works at any granularity, including month, as long as the date table is continuous. Option B is wrong because a divide-by-zero would typically surface as an error or infinity, not blank, and DAX's DIVIDE handles it gracefully. Option C is wrong because an inactive Sales–Calendar relationship would break the measure for all rows, not just some months.

Answer

The measure cannot be used at the month level because SAMEPERIODLASTYEAR only works at year level

Answer

The measure is trying to divide by zero for months with no sales in the previous year

Answer

The relationship between Sales and Calendar is inactive

Question 6

You have a Power BI dataset that includes a 'Sales' table and a 'Calendar' table. You need to create a measure that calculates the running total of sales over the last 12 months, ending on the last date in the current filter context. Which DAX function should you use?

Accepted Answer

DATESINPERIOD. DATESINPERIOD is the correct choice because it returns a table of dates spanning a specified number of intervals (e.g., -12 MONTH) ending on a given date, which is exactly what a rolling 12-month running total requires when combined with CALCULATE and SUM. In this scenario, you would write something like CALCULATE(SUM(Sales[Amount]), DATESINPERIOD('Calendar'[Date], MAX('Calendar'[Date]), -12, MONTH)), where MAX returns the last date in the current filter context. DATEADD shifts a date range by an interval but does not by itself produce a continuous 12-month window ending on the last date. PREVIOUSMONTH only returns the single prior month, not a 12-month span. DATESBETWEEN requires explicit start and end dates and does not automatically anchor to the last date in context with a rolling interval.

Answer

DATEADD

Answer

PREVIOUSMONTH

Answer

DATESBETWEEN

Question 7

You are designing a data model for a report that shows sales by region and product category. The source data includes a table 'Sales' with columns: Region, Category, SalesAmount. You also have separate tables 'Regions' and 'Categories' that contain additional attributes. You need to create a star schema. What should you do with the 'Region' and 'Category' columns in the 'Sales' table?

Accepted Answer

Remove them from the Sales table and use foreign keys to link to the dimension tables. In a star schema, dimension tables (Regions, Categories) contain descriptive attributes, and the fact table (Sales) stores foreign keys referencing those dimensions. Removing the Region and Category columns from the Sales table and replacing them with foreign keys (e.g., RegionID, CategoryID) normalizes the model, reduces data redundancy, and enables efficient filtering and slicing by region and category attributes. This approach aligns with best practices for Power BI data modeling, ensuring optimal query performance and maintainability.

Answer

Keep them in the Sales table as attributes for simplicity

Answer

Merge the Regions and Categories tables into the Sales table

Answer

Mark the Sales table as a date table

Question 8

You are working on a Power BI project for a marketing department. You have a CSV file with customer survey responses. The file contains columns: CustomerID, SurveyDate, Response (text with ratings from 1 to 5), Comments (free text). The file is 10 MB. You need to load the data into Power BI and create a measure that calculates the average rating. However, when you load the file, you notice that the Response column is imported as text instead of whole number. Also, there are some rows with missing values in the Response column. You need to ensure the data is correctly typed and handle missing values appropriately. What is the best approach?

Accepted Answer

Change the data type of Response to whole number in Power Query, then filter out or replace null values.. Power Query is the designated tool for data type transformations and null handling during the load phase. Changing the Response column's data type to Whole Number in Power Query automatically converts valid text numbers and flags errors, while filtering out or replacing null values ensures clean data before the data model is built. This approach follows the best practice of performing data cleansing in Power Query rather than in DAX, which would add unnecessary overhead and complexity.

Answer

Use the 'Column from Examples' feature to create a new column with numeric values.

Answer

In Power Query, split the Response column by delimiter and then use the first part.

Answer

Use a DAX calculated column to convert text to number.

Question 9

You have a Power BI data model with a fact table and multiple dimension tables. You notice that many-to-many relationships cause ambiguous results. What is the best practice to resolve this?

Accepted Answer

Add a bridge table with appropriate relationships. In Power BI, many-to-many relationships between fact and dimension tables can produce ambiguous results because the model cannot determine a unique filter propagation path. The best practice is to introduce a bridge table that resolves the many-to-many relationship into two one-to-many relationships, ensuring unambiguous filter context and correct aggregations.

Answer

Change the relationship to one-to-one

Answer

Use a bidirectional cross-filter direction

Answer

Create a calculated table to merge the dimensions

Question 10

You are building a Power BI semantic model that uses a large fact table from a data warehouse. The fact table has a date column and you want to create a date dimension. The organization requires that the date dimension includes all dates from 2010 to 2030, including weekends and holidays. What is the best practice for creating the date dimension?

Accepted Answer

Create a date table in Power Query by generating a list of dates from 1/1/2010 to 12/31/2030 and then add columns for attributes. It follows the best practice of creating a dedicated date dimension table in Power Query, which ensures full control over the date range (2010–2030) and allows you to add custom attributes like holidays. This approach avoids relying on the fact table's date column, which may have gaps or missing dates, and ensures the date dimension is complete and independent for robust time intelligence calculations.

Answer

Use the CALENDAR function in DAX to generate the date range

Answer

Mark the date column from the fact table as a date table and disable Auto Date/Time

Answer

Create a date dimension by using DISTINCT on the fact table's date column

Question 11

Which TWO of the following are valid methods to share a Power BI report with external users (outside your organization)? (Choose two.)

Accepted Answer

Invite the external user as a guest in your Microsoft Entra ID (Azure AD) and share the report directly with them.. The correct answers are C and E. Option C: By inviting external users as guests in your Microsoft Entra ID (Azure AD) using Microsoft Entra B2B, you can share Power BI reports directly with them without requiring them to have a Power BI license. Option E: 'Publish to web' creates a public embed code that anyone on the internet can view, making it suitable for sharing with external users. Option A is incorrect because exporting to PDF creates a static file, not an interactive report, and is not a sharing method. Option B is incorrect because external users need to be set up as guests or use publish to web; a direct link alone will not work without proper authentication. Option D is incorrect because embedding in SharePoint Online requires the external user to have access to the SharePoint site, which typically involves additional setup such as guest access.

Answer

Export the report to PDF and email it to the external user.

Answer

Send the external user a direct link to the report via email; they can view it without any additional setup.

Answer

Embed the report in a SharePoint Online page using the Power BI web part.

Question 12

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

Accepted Answer

SAMEPERIODLASTYEAR. The SAMEPERIODLASTYEAR function is the correct choice for calculating year-over-year growth because it shifts the current filter context back by one year, returning a set of dates exactly one year prior. This allows you to compute the prior year's sales and then derive the growth percentage using a formula like (Current Sales - Prior Year Sales) / Prior Year Sales.

Answer

DATEADD

Answer

PARALLELPERIOD

Answer

PREVIOUSYEAR

Question 13

You have a Power BI report that uses a measure with a filter context. You want to override the filter context for a specific calculation. Which function should you use?

Accepted Answer

CALCULATE. CALCULATE (option C) is correct because it is the only DAX function that modifies the filter context of a measure, allowing you to override or replace existing filters for a specific calculation by supplying new filter arguments. ALL (option A) is a table function that removes filters from a column or table but does not itself change the evaluation context of a calculation. FILTER (option B) returns a filtered table and is typically used as an argument inside CALCULATE, not as the context-modifying function itself. VALUES (option D) returns a one-column table of distinct values and does not alter filter context.

Answer

ALL

Answer

FILTER

Answer

VALUES

Question 14

You are debugging a Power Query that imports a CSV file. The exhibit shows the M code. The CSV file contains a header row and data. Some rows have a comma inside a quoted field (e.g., "Smith, John"). What issue will arise from this code?

Accepted Answer

The QuoteStyle.None option will cause commas inside quotes to be treated as delimiters.. The M code uses `QuoteStyle.None`, which tells Power Query to treat commas inside quoted fields as column delimiters rather than as part of the field value. This causes rows with values like "Smith, John" to be split incorrectly, resulting in extra columns and misaligned data. The correct option for CSV files with quoted fields is `QuoteStyle.Csv`, which respects the standard CSV quoting rules.

Answer

The encoding 1252 is incorrect for the file.

Answer

The number of columns specified (5) is too many.

Answer

The Promoted Headers step will fail because the first row contains quotes.

Question 15

Which THREE of the following are benefits of using a star schema in Power BI? (Select three.)

Accepted Answer

Simplified DAX formulas. Option A (Simplified DAX formulas) is correct because a star schema separates quantitative facts from descriptive dimensions, so measures typically aggregate a single fact table and filter through one-to-many relationships, avoiding complex bidirectional or multi-table filter logic in CALCULATE and RELATED calls. Option C (Improved query performance) is correct because the Power BI engine (VertiPaq) compresses and scans narrow dimension tables and a single fact table efficiently, and one-to-many relationships let the engine use simpler, faster join paths than snowflaked or normalized models. Option E (Easier for business users to understand) is correct because dimensions map to familiar business entities (Customer, Product, Date) and facts to measurable events, making the model intuitive for self-service report authors. Option B is not correct because star schemas rely on one-to-many relationships; many-to-many relationships are not native to the star design and require bridge tables or special handling. Option D is not correct because increased data redundancy is a drawback of denormalization, not a benefit—star schemas actually reduce redundancy compared with fully normalized models while accepting controlled duplication in dimensions.

Answer

Supports many-to-many relationships natively

Answer

Increased data redundancy