math
posted by Aleah .
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?

Find the number of standard deviations from the mean (above) for each of the limits. For example, (161.28138)/9.7 = 2.4
So look up the normal distribution table and find the fraction (out of 1) that is between the two limits, +2.4 σ and +____ σ.
Change the fraction to percent. 
Is the answer 5%?

Yes, that is correct, well done.
It would be nice if you could get a more accurate table to get a number like 5.x%.