Question: The heights of 18 year old men are approximately normally distributed, with the mean 68 inches and the standard deviation 3 inches.

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. Compare your answers for parts a and b, Is the probability in part b much higher/ why would you expect this?