math
posted by jason .
The mean systolic blood pressure of adult males is normally
distributed with a mean of 138 (millimeters of
mercury) and a standard deviation of 9.7. What percent
of adult males have blood pressure between 161.28 and
164.9?

check out this webpage
http://davidmlane.com/hyperstat/z_table.html
Just enter the mean and sd
click on 'between' and enter your values.