=AVERAGE(IF($B$1:$B$10=1,$A$1:$A$10))

which is an array formula, it should be committed with Ctrl-Shift-Enter, not
just Enter.

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"Sue" wrote in message
...
I would like to sum/average numbers in column A, only if for that row, the
value in column B is a certain value.
e.g. Average column A if value in column B is 1. Then again, average of
column A if value in column B is 2 etc.
A B
4 1
5 2
8 1
7 2
Thanks