# Exam 3 Study Guide: Chapters 18-25

1. Given a sample size and sample proportion, find the standard error, critical z values, margin of error, and confidence interval for the population proportion. Look at activity 6.
2. A confidence interval is given. Find the sample proportion and the margin of error. Use the confidence interval to test a claim.
3. 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. Also, identify whether it is a left tail, right tail, or two-tail test. Look at the figures on page 395 for a start, but most of this is in your notes and the graphs from the activities.
4. Know the concept that is fundamental to all hypotheses testing.
5. 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 values and the standard error for the mean. Find the sample standard deviation and conduct a hypothesis test based on the confidence interval. Look at your notes from chapter 23.
6. A test statistic and the area to the left of the test statistic are given. Give the p-value for a left tail test, a right tail test, and a two tail test.
7. Five statements are given. For each one, decide whether the statement is the null or alternative hypothesis. These are English statements like "The defendant is innocent", not mathematical ones like "12% of adults wet their bed". Remember that the null hypothesis is the normal or assumed condition.
8. Five statements are given. For each one, decide whether it represents a type I or type II error.
9. Three p-values and significance levels are given. In each case, decide whether to reject or retain the null hypothesis.
10. Five 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. These are mathematical statements like "the average adult earns \$35,000 a year". They could be about one or two proportions or means. If there are two samples, be sure to define the subscripts or use subscripts that make sense.
11. Five critical value(s) and test statistics are given. For each case, decide whether it is a left tail, right tail, or two tail test and whether to Reject H0 or Retain H0.
12. Three confidence intervals are given along with a null hypothesis. Decide whether the test is left tailed, right tailed, or two tailed and whether you would reject or retain the null hypothesis.
13. Work a hypothesis test. It could be about one or two proportions or means. 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. Identify key values from the problem. Use a table to look up the critical value(s). The test statistic, p-value, and/or confidence interval from Minitab are given, use them to make a decision and then write the conclusion. Look at activities 6, 7, 8, and 9.
14. Similar to #13
15. Similar to #13

## Notes

• There are formulas for the mean and standard error for sample proportions and sample means provided on the test. It is up to you to know how and when to use them.
• You will definitely want a calculator.
• When probabilities are asked for, they should be given as decimals.
• The Student's t table will be supplied with the exam

## Points per problem

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