The heights of American women ages 18 to 29

Question

The heights of American women ages 18 to 29 are normally distributed with a mean of 64.3 inches and standard deviation of 3.8 inches. An American woman in this age bracket is chosen at random.

What is the probability that she is less than 70 inches tall?







b. What is the probability that she is between 64 and 69 inches tall?

Answer 1

a)  Calculate the z-score for x=70:  z = (70-64.3)/3.8   Then use the standard distribution table to find the decimal value for that z score; convert to % by shifting decimal point two places toward the right.

 

b)  calculate two z-scores, one for 69" & other for 64"

Take the difference between their associated probabilities & convert to %