Updated the details now
Sorry i forget to add the dimension details
Check your output with the expected manual result if it gives result then it will correct other wise you can use Avg function for this. And if the fields which is in Numerator or denominator has proper relation then it will correct for you.
You can also try with
=Aggr( sum(Dollars)/Count(standardID), DimensionName )
=Avg( Aggr( sum(Dollars)/Count(standardID), DimensionName ))