Hourly Wages Number of Wages Bins Midpoints
$  4 up to $  7 18 7 5.5
  7 up to   10 36 10 8.5
 10 up to   13 20 13 11.5
  13 up to   16 6 16 14.5

This did not post the way I wanted.

Hourly Wages Number of Wages Bins Midpoints
$  4 up to $  7 18 7 5.5
  7 up to   10 36 10 8.5
 10 up to   13 20 13 11.5
  13 up to   16 6 16 14.5

I cannot get my histogram in excel to come out correctly. It keeps coming up with a 0 frequency on two of these. That doesn't seem correct... is it?