For women aged 18-24, systolic blood pressures (in mm Hg) are
normally distributed with a mean of 114.8 and a standard deviation
of 13.1. Hypertension is commonly defined as a systolic blood
pressure above 140.
a. If a woman between the ages of 18 and 24 is randomly
selected, find the probability that her systolic blood pressure is
greater than 130.
b. If 25 women in that age bracket are randomly selected, find
the probability that their mean systolic blood pressure is greater
than 130.