weighted average with months

[#1]

Hi all,

I have:

Customer

Qty

Value

Month

I should calculate a weighted average of quantity starting with the month in which the Customer has been activated

i.e

Customer #1

Month/Quantity

Mar: 4

Sep: 7

Dec:10

My weighted average is: 2,1 [(4+7+10)/10] 10 Months because I don't count Jan+Feb when the customer did not exist.

I wonder how to make it in qlik...

Any suggestion would be really appreciated! Thanks in advance!

[#2]

I have partially solved my problem using Max(Month) - Min(Month). Partially because if Max(Month) considered has a Null QT, it is not counted in my average.. Any idea to solve this problem? thanks in advance

[MarcoWedel]

Please share a sample application