Averaging percentages

Giganews Newsgroups
Subject: Averaging percentages
Posted by:  Marketing analyzr (dugay…@gmail.com)
Date: 24 May 2006

This is actually a basic mathmatical question but its a stumper for me.

Can you average a column of percentages and get a true average?
I've been told that it can't be done accurately but I never understood
the expanation.

thanks in advance
Marketing Analyzr