Jon
Speaking as a recovering statistics instructor, DON'T! Averaging
percentages is bad math.
Instead add up all the underlying values and do your division/percentage
conversion on that number.
Here's an illustration (extreme) of why:
1 in 2 is 50%
1 in 1,000 is 0.1%
The average of the percentages is very close to 25%.
The average of the underlying numbers is very close to 0.2%.
Which do you think is more accurate?
--
Regards
Jeff Boyce
www.InformationFutures.net
Microsoft Office/Access MVP
Microsoft IT Academy Program Mentor
http://microsoftitacademy.com/
