Microsoft Power BI Data Analyst Associate Study Guide

Appendix. Solutions to the Practice Questions

This appendix lists the solutions to the practice exam questions appearing at the end of Chapters 2 through 5.

Chapter 2

1. Correct answer: C. See “Assessing and Improving Data Quality”.

   Rationales:

   1. Data type selection can affect column sorting under certain conditions and only for certain data types, but this is not the primary benefit.

   2. Data type choice doesn’t guarantee correct visualization. This is a component of data transformation and modeling, which is preparatory to visualization, but not the primary benefit.

   3. Choosing the most appropriate data type in the Get Data experience can improve query performance and minimize storage size because it improves compression for the values in the column.

   4. Changing column data type in queries doesn’t improve load time.

2. Correct answer: A. See “Data Transformations” and “Assessing and Improving Data Quality”.

   Rationales:

   1. Create data cleansing transformations in Power Query to resolve data-quality issues before data gets to the report layer.

   2. Cleansing data is not directly related to optimizing report layout, but many report issues are avoided by transforming and shaping data prior to report design.

   3. Filtering data in report visuals is only a workaround for data quality issues. It would be better to correct erroneous data and prevent the need to filter it in the report.

   4. Performing endorsement, promotion, and certification can set user expectations regarding report data quality ...