Can someone please help me to find a way round my problem. Here is a sample of


A B C D E
Product City Price Room night
H1 ROME 100.00 15
H2 LONDON 105.00 100
H3 ROME 203.00 5
H4 ROME 150.00 115
H5 LONDON 200.00 5

This is what I need.
On Column E I need the weighted average price for H1 based on room night.

Thanks.