I believe you need to do a weighted average of the %s, not an average. To do
that use

=SUMPRODUCT(A2:A81,C2:C81)/SUM(A2:A81)

you should come up with the 3.46% figure.




"Robin Blackwell" wrote:

Hi all,

I have an Excel function query that's really bugging me. In column "A" I
have about 80 staff annual salaries. In column "B" I have their
corresponding annual salary increase.

If I sum Column "A", and sum Column "B", and divide the resultant totals, I
get what I assume to be the average annual salary increase for the group
(3.46%).

However, if in Column "C" I calculate each individual's average annual
increase (B2/A2 etc), and then use the AVERAGE function over all of the
results in column "C" I get a different answer (3.79%).

Why is this please, and which answer is correct?

Thanks,

Robin