I would have never guessed. Median is the middle number of any grouping of numbers. Example: 10, 20, 30, 90, 10000. The median is 30. The average would be 2030. Median is a good way to describe a population since the outliers are essentially thrown out of the equation.Uh, I'm no math whiz (he said yet again), but MEDIAN and AVERAGE are very different.
Disparity in succes has a lot more to do with size than income, though one usually comes with the other. People who can move, move to the best schools which contributes to their larger size.