Hi I would like get weighted average margin by category.
I want to use the sales to weight the margins.
Any help? thanking in advance
<colgroup><col><col><col span="2"><col></colgroup><tbody>
A
B
C
D
1
Invoice Number
Product
Sales
Margin
2
22
Pen
110
15%
3
28
Books
200
11%
4
26...