Conditional average by month

[slatka11]

I am looking to write a DAX to calculate the average skid count by month but the average should take the sum of the skids in an order group if there is one. Below is the sample data. 

For example, the February average should calculate as 10 in the sample data because there is a group, and January should calculate as 10.83 ((21+3+21+4+2+14)/6). 

ORDER_NUMBER	ORDER_GROUP_ID	SKID_COUNT	SHIP_DATE
801676		21	1/1/2022
801762		3	1/1/2022
801772		21	1/1/2022
801782		4	1/1/2022
801836		2	1/1/2022
801697	801697	4	1/1/2022
801736	801697	5	1/1/2022
801780	801697	5	1/1/2022
801787	801787	4	2/2/2022
801799	801787	4	2/2/2022
801815	801787	2	2/2/2022

[ppm1 · Accepted solution]

Here's a measure expression that shows one way to do it.

Avg Skid_Count =
//var NoGroupSum = CALCULATE(SUM(T6[SKID_COUNT]), ISBLANK(T6[ORDER_GROUP_ID]))
VAR NoGroupCount =
    CALCULATE ( COUNT ( T6[SKID_COUNT] ), ISBLANK ( T6[ORDER_GROUP_ID] ) )
VAR OrderGroupCount =
    DISTINCTCOUNTNOBLANK ( T6[ORDER_GROUP_ID] )
VAR TotalSkidCount =
    SUM ( T6[SKID_COUNT] )
RETURN
    DIVIDE ( TotalSkidCount, NoGroupCount + OrderGroupCount )

Pat

[slatka11]

Thank you Pat, this works!