In the second DAX measure example, which expression should replace <ANSWER HERE> to calculate the average of responses?

• A. AVERAGE('Survey'[Response Value])
• B. SUM('Survey'[Response Value])
• C. COUNT('Survey'[Response Value])
• D. Average('Survey'[Response Value])

Answer: (D)

When you want the average of a numeric column in DAX, use a function that computes the arithmetic mean directly. The expression Average('Survey'[Response Value]) does just that: it takes the values in the Response Value column and returns their mean, within the current filter context. DAX function names are not case-sensitive, so Average and AVERAGE are interchangeable, which is why this form is valid even though the other case variant is shown with a different capitalization.

This approach is the correct way to obtain the average because it calculates the mean rather than a total or a count. Sum would add all values, and Count would number how many non-blank entries exist, neither of which gives the average. The average function ignores blanks, which is typically the expected behavior when calculating a mean across a dataset.