Ok. More reading, and I'm understanding about the hip thing. But the waist split is giving me a little trouble. Here's an example... would someone please explain why one is better than the other.

W: 33
H: 38

This is example #22 from p122 of TAoKM. I got the hips right w/ 18.5/19.5, but I guessed wrong on the waist split: 17/16. The book says 17.25/15.75. Not a lot of difference, but this is why I was only a C-grade math student.