Question: The height of a 18 year old men normally with mean 68 inches and standard deviation 3 inches.

(a) what is the probability that an 18 year old man select 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 xbar 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?