When I create the sum by month, by product, the numbers appear correct.
However, when I create a monthly average (which I assume would be aggregate total/divided by days in the month) the number isn't correct. I'm not sure why.
The only reason I can think of is this: On some of the products the sku changes, so for 1/2 the month those skus (rows) will show 0. Does this monthly average get divided at the row level? How can I get around this?