Try this array formula** :

=AVERAGE(IF(A1:A10=1,B1:B10))

** array formulas need to be entered using the key combination of
CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT
key then hit ENTER.

--
Biff
Microsoft Excel MVP


"bob$" wrote in message
...
AVERAGE a range in a column if a a value in a different column equals "1"