I don't remember any of my calculus but I am haunted by the memory of my statistics classes.

Take a standard distribution. On the std symetric bell curve, the mean and the median are equal and bisect the hump of the curve. The area contained beneath the graph is equal on both sides of the median. Stretch the curve in one direction or the other and the mean follows the extremes more than the median.

If asked this question on a test: Given a population of whiney pilots, paid between $20k a year and $400k a year with a government provided median value of $135k a year, is the mean value less or more than $135? You honestly don't have the data to answer the question without a doubt. However, in any kind of statistical distribution that didn't exhibit the dreaded "double hump!" the mean will tend towards the extreme values.

If you are thinking about some double-humped distribution, then the mean can be anything. I don't think this is possible considering that there's really not that many pilots on the very low end of the scale and that for every regional F.O. on food stamps, there's a Captain sitting right next to him who is making twice his income, meaning there's probably not a sharp spike on the left side of the population.