I am new to Tableau and am trying to multiply Booked_Qty times Forecast Error % to get a weighted quantity. I think the Booked_Qty is aggregated and the Forecast Error % calculated field is non-aggregated. I am getting the "cannot mix aggregate and non-aggregate arguments to function." error. The basic formula logic is:
([Booked_Qty] * [Forecast Error])
Please see attachment.
Try this (booked_qty] * max([forecast error])