Help with Weighted Average Per Month
 

This is Sheet 1 of my workbook.
A Date(ie 2-Feb-2007) B Cycle Count # C # Items Selected D # Of items With
Variance E % Accuracy F $ Variance G YTD Items Selected
H YTD % Accuracy

Each Heading is a Column labeled by the letters A - H

On Sheet three I have this.
A Month B # Cycle Counts C # Items Selected D # Of items With Variance E %
Accuracy

The problem I am having is caluclating a weighted average for E on the third
sheet using the data on sheet one.
Any Help would be very much welcome !