1. What is a"sampling distribution" of the sample mean, xbar? Explain.

2. Is x-bar (sample mean mentioned in #1) a random variable? Why do you think/not think so?

3. In chapter 8, we learned standard error of the mean ( read sigma xbar in denotation) or standard deviation of sample mean. Let's say the size(n) of the sample collected from a infinite population is greater than 1.

Compare "thestandard error of the mean "with "the standard deviation of X, population ". Which is smaller? Why? Explain conceptually or/and algebraically. Think of formula for Standard error of the mean (sigma xbar).