Conditional Columns

Originally Posted by BenMiller

That would give you the sum. To average it, try

=SUMPRODUCT(--(TEXT($A$2:$A$19,"mmmm")=D2),$B$2:$B$19)/SUMPRODUCT(--(TEXT($A$2:$A$19,"mmmm")=D2))

When I tried this, I got #DIV/O!