# Exam 6 Study Guide: Chapters 23-25

1. A sample size and confidence interval for the population mean are given. Find the sample mean and the margin of error. Find the critical t value(s) and the standard error fo the mean. Find the sample standard deviation and conduct a hypothesis test based on the confidence interval. Look at your notes from chapter 23.
2. Know how to check normality from a probability plot. The sample size, mean, and standard deviation are given, find the standard error. Find the critical t value(s) and the margin of error. Find the confidence interval for the mean. Conduct a hypothesis test based on the interval.
3. Work a hypothesis test. It could be about a single population mean, two independent samples, or a paired sample. For two samples, decide if the samples are independent or dependent. Write the original claim symbolically and decide if it is the null or alternative hypothesis. Write H0 and H1 and identify it as a left tail, right tail, or two tail test. The test statistic, p-value, and sometimes the degrees of freedom from Minitab are given, use them to find the critical value(s), make a decision, and then complete the conclusion.
4. See #3.
5. See #3.
6. See #3.
7. Three pairs of statements are given. For each one, decide which statement is the null hypothesis and which statement is the alternative hypothesis. These are English statements, not mathematical ones.
8. You are given a test statistic and critical value(s). Decide whether it is a left tail, right tail, or two tail test and whether to Reject H0 or Retain H0. Three parts.
9. Know the concept that is fundamental to all hypotheses testing.
10. A graph of a probability distribution is given along with a critical value and level of significance. Draw and label a vertical line at the critical value, shade and label the critical region, label the non-critical region, label each region with the area in that region, write "Reject H0" and "Retain H0" in the appropriate regions of the graph.
11. A claim is made and a statistical test that you've never seen before is performed. Use the critical value and test statistic to decide whether to reject or retain the null hypothesis. Complete the conclusion.
12. Three pairs of statements are given. For each pair, decide which is a type I error and which is a type II error.
13. A p-value and significance level are given. Decide whether to reject or retain the null hypothesis. Two parts.
14. A null hypothesis and a confidence interval are given. Decide whether the test is left tailed, right tailed, or two tailed and whether you would reject or retain the null hypothesis. Two parts.
15. Four claims are given. For each claim, write the null and alternative hypotheses and determine whether it is a left tail, right tail, or two tail test. If there are two samples, be sure to define your subscripts.

## Notes

• A copy of the Student's T table will be provided.
• You will definitely want a calculator.
• Do not waste a lot of time on the first two problems. They are probably the two most difficult ones on the test.

## Points per problem

 # Pts 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Total 8 9 13 11 9 11 3 6 1 5 3 3 2 4 12 100