SUM and AVERAGE functions in Power BI - Cell-by-Cell Formula Trace

Sample Data

This table shows sales and costs data for three products.

Cell	Value
A1	Sales
A2	100
A3	200
A4	300
B1	Costs
B2	50
B3	80
B4	70

Formula Trace

SUM(A2:A4) + AVERAGE(B2:B4)

Step 1: SUM(A2:A4)

Step 2: AVERAGE(B2:B4)

Step 3: 600 + 66.6667

Cell Reference Map

    A       B
1 |Sales | Costs |
2 | 100  |  50   |
3 | 200  |  80   |
4 | 300  |  70   |

SUM uses cells A2, A3, A4
AVERAGE uses cells B2, B3, B4

The formula uses sales values from A2 to A4 and cost values from B2 to B4.

Result

    A       B       C
1 |Sales | Costs | Result |
2 | 100  |  50   |        |
3 | 200  |  80   |        |
4 | 300  |  70   | 666.67 |

The result 666.67 is shown in cell C4, which is the sum of sales plus average of costs.

Sheet Trace Quiz - 3 Questions

What is the result of SUM(A2:A4)?

A 600

B 500

C 300

D 700

Key Result

SUM(range) adds all numbers in the range; AVERAGE(range) calculates the mean of numbers in the range.

Practice

1.

What does the SUM function do in Power BI?

easy

A. Adds all numbers in a column

B. Finds the highest number in a column

C. Counts the number of rows

D. Calculates the average of numbers

Solution

1. Step 1: Identify the purpose of SUM

   The SUM function adds all numeric values in a specified column, unlike AVERAGE (mean), COUNT (rows), or MAX (highest).

2. Final Answer:

   Adds all numbers in a column -> Option A

3. Quick Check:

   SUM = total addition [OK]

Hint: SUM always adds numbers, not counts or averages [OK]

Common Mistakes:

• Confusing SUM with AVERAGE
• Thinking SUM counts rows
• Mixing SUM with MAX or MIN

2.

Which of the following is the correct syntax to calculate the average of the Sales[Amount] column in DAX?

?

easy

A. SUM(Sales[Amount]) / COUNT(Sales[Amount])

B. AVERAGE(Sales[Amount])

C. AVG(Sales[Amount])

D. MEAN(Sales[Amount])

Solution

1. Step 1: Recall correct DAX average syntax

   In DAX, use AVERAGE(Sales[Amount]); AVG() and MEAN() do not exist, while SUM/COUNT works but is indirect.

2. Final Answer:

   AVERAGE(Sales[Amount]) -> Option B

3. Quick Check:

   AVERAGE() is the direct DAX function [OK]

Hint: Use AVERAGE() directly for mean in DAX [OK]

Common Mistakes:

• Using AVG() which is not a DAX function
• Trying MEAN() which doesn't exist in DAX
• Dividing SUM by COUNT manually instead of AVERAGE

3.

Given the table Sales with Amount values: 100, 200, 300, what is the result of this DAX measure?

TotalAmount = SUM(Sales[Amount])
AverageAmount = AVERAGE(Sales[Amount])

What are the values of TotalAmount and AverageAmount?

medium

A. TotalAmount = 600, AverageAmount = 200

B. TotalAmount = 300, AverageAmount = 100

C. TotalAmount = 600, AverageAmount = 300

D. TotalAmount = 200, AverageAmount = 600

Solution

1. Step 1: Compute SUM and AVERAGE values

   SUM(100 + 200 + 300) = 600; AVERAGE = 600 / 3 = 200.

2. Final Answer:

   TotalAmount = 600, AverageAmount = 200 -> Option A

3. Quick Check:

   SUM = 600, AVERAGE = 200 [OK]

Hint: Sum all values; average is sum divided by count [OK]

Common Mistakes:

• Mixing sum and average values
• Dividing sum by wrong count
• Confusing average with max or min

4.

Identify the error in this DAX formula intended to calculate the average sales amount:

AverageSales = SUM(Sales[Amount]) / COUNT(Sales)

medium

A. SUM should be replaced with AVERAGE

B. SUM cannot be divided by COUNT

C. No error, formula is correct

D. COUNT(Sales) should be COUNT(Sales[Amount])

Solution

1. Step 1: Locate COUNT syntax error

   COUNT(Sales) is invalid as COUNT requires a column like Sales[Amount], not a table.

2. Final Answer:

   COUNT(Sales) should be COUNT(Sales[Amount]) -> Option D

3. Quick Check:

   COUNT needs a column, not a table [OK]

Hint: COUNT needs a column, not a whole table [OK]

Common Mistakes:

• Using COUNT with a table instead of a column
• Assuming SUM/COUNT division is invalid
• Replacing SUM with AVERAGE without reason

5.

You have a Sales table with columns Region and Amount. You want to create a measure that shows the average sales amount only for the "East" region. Which DAX formula correctly calculates this?

?

hard

A. AverageEastSales = AVERAGE(Sales[Amount]) WHERE Sales[Region] = "East"

B. AverageEastSales = AVERAGE(FILTER(Sales, Sales[Region] = "East"))

C. AverageEastSales = CALCULATE(AVERAGE(Sales[Amount]), Sales[Region] = "East")

D. AverageEastSales = SUM(Sales[Amount]) / COUNT(Sales[Region] = "East")

Solution

1. Step 1: Construct correct filtered average DAX

   Use CALCULATE(AVERAGE(Sales[Amount]), Sales[Region] = "East") to apply filter context; others invalid (no WHERE, AVERAGE can't take table from FILTER directly, COUNT misused).

2. Final Answer:

   AverageEastSales = CALCULATE(AVERAGE(Sales[Amount]), Sales[Region] = "East") -> Option C

3. Quick Check:

   CALCULATE + filter = correct average [OK]

Hint: Use CALCULATE with filter for conditional averages [OK]

Common Mistakes:

• Using WHERE clause which is invalid in DAX
• Trying to filter inside AVERAGE directly
• Dividing SUM by COUNT with filter incorrectly