Self-review: Transforming multiple data sources :Extract, Transform and Load Data in Power BI (Microsoft Power BI Data Analyst Professional Certificate) Answers 2025

Question 1

What is the number of columns remaining after you remove the unnecessary ones from the OrderDetails query?

❌ 3
✅ 4
❌ 5

Explanation:
After cleaning the OrderDetails query and removing unnecessary columns, only the essential fields remain, resulting in 4 columns.

Question 2

True or False: In the Order Details query, when you remove the anomaly values there are 27 distinct and 6 unique values for the UnitPrice column.

❌ True
✅ False

Explanation:
After removing anomaly values, the counts of distinct and unique values do not match the stated numbers, so the statement is incorrect.

Question 3

In the OrderDetails query, how many rows are there after you remove anomalies?

❌ 996 rows
✅ 997 rows
❌ 999 rows

Explanation:
Only the anomalous records are removed, leaving 997 valid rows in the dataset.

Question 4

What is the reason for using an Inner Join for the merge operation of OrderDetails and Order?

✅ To keep only matching rows between the two tables.
❌ To keep all the rows from the right table.
❌ To keep all the rows from the left table.

Explanation:
An Inner Join ensures that only records with matching keys in both tables are included.

Question 5

By removing data anomalies in the sales data, what impact does this have on the business?
(Select all that apply)

✅ It improves data accuracy.
✅ It improves integrity of the data source.
✅ It improves decision making.

Explanation:
Clean data leads to accurate analysis, maintains data integrity, and supports better business decisions.

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