This little applet is just perfect for your kind of question.
Just enter the data as you have it and choose the "between" option
http://davidmlane.com/hyperstat/z_table.html
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?
1 answer