Calculations after Grouping - How do you limit calculations to a single group?

Hi All,

I am new to the forum and not an Excel expert. What I am trying to do is to take very large data files, subdivide the data in into groups, run various calculations on those subsets/groups of data, and classify the results. I can subset/group the data and get it to do sums/average/etc. on those subgroups, but I need to calculate more than just the standard set of basic statistics. I want to enter in other formulae and run those on the subgroups and the derivatives from those calculations.

I have attached a very small sample worksheet with some formulae and more explanation. I am stumped on how to reference the group number for the calculations.

Thanks for any help you might be able to provide.