Vital Statistics: Heights of Men The heights of 18-year-old men are approximately normally distributed, with mean 68 inches and standard deviation 3 inches (based on information from Statistical Abstract of the United States, 112th edition).

(a) What is the probability that an 18-year-old man selected at random is between 67 and 69 inches tall?

(b) If a random sample of nine 18-year-old men is selected, what is the probability that the mean height x is between 67 and 69 inches?

(c) Interpretation Compare your answers to parts (a)

and (b). Is the probability in part

(b) much higher?

Why would you expect this?

AppendixLO1