Hi.

I am trying to work out a sum of a range of cells, but only if another cell in the row that contains the number meets a certain criteria.
eg. (forgive formatting)

     A     B     C     ...

1  100  x
2  110  y
3  105  z
4  105  x
5  120  y
6  110  x


I want an average of everything with 'x' in column b.

I know how to count the number of x's in column b using COUNTIF, what I want is a SUM of all items in Column A that have an 'x' in column B.

Gurus...