for pre-2007:
=SUMIF(Q3:Q502,"Yes",S3:S502)/COUNTIF(Q3:Q502,"Yes")

--
Best Regards,

Luke M
"Eduardo" wrote in message
...
Hi,

=AVERAGEIF($Q$3:$Q$502,"YES",$S$3:$S$502)

"Doug" wrote:

I have reference data in Column "$Q$3:$Q$502" of "sheet1". For all cells
in
the reference column that contain "yes", I would like to average quantity
in
cells for Column $S$3:$S$502 respectively.

So if it finds 3 in column Q with "Yes" (2,3,4) , it will return the
number 3.
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Thank you!