Weighted Averages

A weighted average is the sum of each result multiplied by the weighting applied to it, divided by the sum of the weighting.

So, in your example, assuming your data was in cells A2:D5, the average for your first row would be:

=(C2*0.25)+(B2*0.75)

Which would give 5.625.

I was going to upload my spreadsheet (I've only just got in from work), but that seems to have done it.

Thanks! I was clearly over thinking things!

Matt