the shocking fact that in the LA County school district almost half of the children scored below average on a reading test.

If the group is large enough to follow a normal distribution (bell curve or Gaussian distribution) then of course half would score below average, and half would score above average (mean = median for this distribution)!

This is reminiscent of the argument that "[insert province]'s [insert medical professional] are the lowest paid in the country, and isn't that scandalous?" Well, if they weren't, someone else would be!