"Nearly everyone is above average
by JOHN on OCTOBER 20, 2008
Most people have a higher than average number of legs.
The vast majority of people have two legs. But some people have no legs or one leg. So the average number of legs will be just slightly less than 2, meaning most people have an above average number of legs. (I didn’t come up with this illustration, but I can’t remember where I saw it.)
Except in Lake Wobegon, it’s not possible for everyone to be above average. But this example shows it is possible for nearly everyone to be above average. And when you’re counting numbers of social connections, nearly everyone is below average. What’s not possible is for a majority of folks to be above or below the median.
Most people expect half the population to be above and below average in every context. This is because they confuse mean and median. And even among people who understand the difference between mean and median, there is a strong tendency to implicitly assume symmetry. And when distributions are symmetric, the mean and the median are the same".
http://www.johndcook.com/blog/2008/1...above-average/
