>"at least half of all people are at or below median"
Take the median of
1 2 5 5 5 5 8 9 11 23 58 46 48 37 28 67 39
Much less than half of the numbers are at or below the the median of 5.(also median would be a bad way to get an average for this set.)
(Sorry, I just couldn't resist. It seemed apropos to the overall conversion. :)