Weighted average inside group of cells

[kurtwagner]

Hello,

I'm having the following problem:

I have a sheet with columns for the transport number, the invoice for the each good transported, the freight for each good and the weight.

Problem is, the weight is the total weight of the goods in each transport.
I need a macro that creates a new column that divides the weight based on the freight cost for each invoice in each transport - a weighted average.

Please see attached table for clarification.

[Bob Phillips]

You need to explain how you arrive at those weighted values, I cannot see where they come from.