If you want Group numbers instead of alternating A, B - you can put the
following in column A and copy down the column.

="Group "& INT((ROW()+18)/20)

18 was determined by 20 minus the row number of the first row that actually
contained the data. My data started in row 2 so 20-2=18, adjust as needed.
Then select Column A copy, then click Edit/Paste Special/values to hardcode
the group numbers. Then use Subtotal.


"Karen K" wrote:

I have a data of 14000 rows. I need Average on every 20 cells. Instead of
copying and pasting the formula into every 20 cells to get the result which
will take forever is there a function to obtain the results automatically?

I'm trying group every 20 rows automatically unfortunately it didn't help
either. Help!