A survey was conducted to measure heights of U.S. men. In survey respondents were grouped by age. In the 20-29 age group the heights were normally distributed with the mean of 69.5 inches and standard deviation of 4.0 inches. A study participant is randomly selected.
a.) Find out the probability that his height is less than 67 inches.
b.) Find out the probability that his height is between 67 and 71 inches.
c.) Find out the probability that his height is more than 71 inches.