Problem 134

Problem 134

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?

Solution

Z = $\frac{x - mean}{standard deviation}$

Z(161.28) = $\frac{161.28 - 138}{9.7}$ = 2.4

Z(164.9) = $\frac{164.9 - 138}{9.7}$ = 2.773

Percent of adult males (2.4 < z < 2.773 ) = 49.72% – 49.18% = 0.54%