The heights of women in the US approximately follow a bell shaped curve. What do you think that means?

Answer 1

It means that heights (h) are distributed according to a formula

N(h) = exp-[(h-m)/a)]^2 , where
m is the most probable (and average) height
a is the standard deviation, sometimes called sigma

If you plot N vs. h, it looks like an upside-down bell.