Question

If the measure of systolic blood pressure is normally distributed with a mean of 120 and a standard deviation of 10, find the probability that a randomly selected person will have a systolic blood pressure below 130. Assume systolic blood pressure is normally distributed.

Answer 1

Solution:

Given, $\mu=130,\sigma=10$

$z=\dfrac{X-\mu }{\sigma}$

$P(X<130)=P(z<\dfrac{130-120 }{10})$

$=P(z<1)=0.84134$ [Using z-score table]