=AVERAGE(IF(B1:B100=1,A1:A100))

entered with ctrl + shift & enter, if there can be blanks in A

=AVERAGE(IF((A1:A100<"")*(B1:B100=1),A1:A100))

--
Regards,

Peo Sjoblom

Northwest Excel Solutions

Portland, Oregon




"vinnie123" wrote in message
oups.com...
Hi everyone. I've a spreadsheet with one column (eg. A1:a100)
containing a range of values (ages) and another column (B1:100) a value
of either 1 or 2 (representing males vs females).

How can a find the average of the cells A1:A100 that have a value of 1
in column B; ie. the average age of the males only.

Thanks