I have a simple spreadsheet, in columns A and B are months of the year (from
Jan 90 to present) and the Annual Inflation Rates for those years...

In cell E4, I enter Month X, and in F4 I enter Month Y

I need to work out the average of the corresponding inflation rates BETWEEN
those two months

e.g. if X is Jan 90 and Y is March 90, I need to find out the average of the
inflation rate for Jan Feb and Mar 90.

Anyone think they might be able to help me? I'm completely stumped!

Thanks
Daniel