I don't think you're interpreting Dominic correctly.

If your regions have different numbers of items, then the average of all
the items will not normally be the average of the region's average. For
instance:


Region 1: 100, 40, 60, 20 == Average: 55
Region 2: 70, 80 == Average: 75
Region 3: 60, 60, 60 == Average: 60

The average of all items (100, 40, 60, 20, 70, 80, 60, 60, 60) is 60.5.

However the grand average, or the average of the averages (55, 75, 60)
is 61.11111111

To get the averages to total to the grand average:

=((4 * 55) + (2 * 75) + (3 * 60))/9 == 61.11111111

If that's not the issue, it may be a difference due to rounding - most
numbers can't be represented exactly in a finite number of binary
digits. See

http://cpearson.com/excel/rounding.htm

or

http://www.mcgimpsey.com/excel/pennyoff.html

but 0.3 seems like a rather large difference to be due to this.

In article .com,
" wrote:

That is my problem! I am NOT a sumproduct pro also... I placed out the
decimal point to 30 and it just does not come out correct. To my
knowledge there is not a mathematical issue here, so it must be in
Excel or most likely just in sumproduct. Does anyone else out there
have a clue as to why this happens???