Exam 4 Study Guide: Chapters 7-8

1. 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. Most of this is in your notes and the graphs from the activities.
2. Know the concept that is fundamental to all hypotheses testing.
3. 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.
4. 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.
5. Five statements are given. For each one, decide whether it represents a type I or type II error. For example, "A blood test comes back negative (not infected) when the person really is infected" is a type II error because the normal condition of a person is that they are not infected. Since they actually are infected, the null hypothesis is false and we are retaining a false null hypothesis.
6. Three p-values and significance levels are given. In each case, decide whether to reject or retain the null hypothesis.
7. 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.
8. Circle the correct response so that the conclusion is properly worded. Three parts.
9. 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.
10. Determine whether the given statement is the null hypothesis or the alternative hypothesis. These are symbolic statements like p=0.42, not English statements like in question 4.
11. A statistical test that you've never heard of is conducted and the p-value and null hypothesis are given. Write the decision and give the conclusion.
12. 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.
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, and 8.
14. Similar to #13
15. Similar to #13

Notes

• You will need a calculator for the test.
• In questions 13 - 15, two tail probabilities from Minitab are given. If your hypothesis test is a one tail test, then you will need to divide the p-value by two.
• A t-table will be supplied so that you can look up critical values.
• A review exercise with sample problems is available.

Points per problem

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Last updated November 2, 2005 7:10 AM