91Ó°ÊÓ

What is the standard deviation of a sampling distribution called?

List two unbiased estimators and their corresponding parameters.

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, 112 th 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 \(\bar{x}\) 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?