GW07 Sampling Distributions:  Study Guide
Due in class on Monday, Jan 28.

Note:  Include each question followed by its answer.
1 What is the relation between sample size and how well the sample represents the population?
2 What is sampling error?  How is it similar to "standard deviation?"
3 What is a sampling distribution?  What is the sampling distribution of the mean?
4 How do sampling distributions differ from distributions of scores?
5 What are three "predictable and useful characteristics" of the distribution of sample means?
6 State the Central Limit Theorem (CLT), and note two facts which underscore its value.
7 What is the critical # of scores in a sample size such that the distribution of sample means will be
    "almost perfectly normal?"
8 What are the two conditions, either of which will ensure that the distribution of sample means will
    be normal?
9 When n > 30, what is the relation between the shape of the sampling distribution of the means and
    the shape of the original population?
10 What is the average value of all the sample means?  What is the "formal statement" of this
      phenomenon?  What is the name for this value?
11 What is the standard error of the mean?  Why is it useful?
12 Explain the similarities and differences among standard deviation, standard error of estimate, and
     standard error of the mean.
13 Identify and explain the two characteristics of the population which determine the numerical value
     of the standard error.
14 State and explain the formula for the standard error.
15 What is the primary use of the distribution of sample means?
16 State the formula for z-score corresponding to any sample mean and explain how & why it differs
     from the z-score for individual scores.
17 Explain how standard error indicates probability or chance regarding the relation between
     an unknown population mean & the sample mean. [Note:  this is not the z-score/unit normal table
     procedure.  Rather, "Larger standard error . . ..  Smaller standard error. . .."]
18 Explain how standard error is useful  in measuring reliability and in measuring stability.