Math
posted by PDub .
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?

Try this wonderful program,
http://davidmlane.com/hyperstat/z_table.html
You can convert to data to zscores or use it directly
It is preset for a mean of 0 and SD of 1