The authors state that the heights of women in North America are normally distibuted with a mean of 65.0 and a standard deviation of 3.5 inches. I am 64.5 inches. Using the parameters above, what percent of women in North America are shorter than I am?

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Multiply by 100.