calculating weighted average

[Anonymous]

Hello all ,

I want to have a dax formula to calculat the weighted average for the next scenario.

i have 10 participants , which 8 participants scored a 1 and 2 participants scored a 4.

So based on this the weigted average would be =  8 x 1 + 2 x 4 = 8 + 8 = 16 / 10 = 1.6

Which DAX formula should i use to get 1.6?

Thanks in advances.

Rega

[Molotch]

Not sure I follow you. Why would you go through the trouble grouping the 1:s and 4:s and then calculate a weighted average when you have all the individual scores and can just use a straight average?

If you have the average and weight in a table you can use SUMX to do a row by row calculation where you multiply your average with the weight and then divide the result by the SUM of the weights. That will calculate the weighted average. Ie SUMX(table, average*weight)/SUM(weight).

It can be quite slow though since it iterates all rows in the table.

[erik_tarnvik · Accepted solution]

If Scores is your table then 

Measure = SUM(Scores[Score])/COUNTROWS(Scores)

should do it. Your formula is equivalent to just summing up the scores column and divide by number of rows, right?