Chapter 8 – Study Notes

 

1. Up to this point, we have worked with ___ sample. In this chapter, we will compare ___ ____ of sample data.
2. Two samples are _____________ if the sample values selected from one population are not related to or somehow paired with the sample values selected from the other population.
3. If the values in one sample are related to the values in the other sample, the samples are __________.
4. It is important to understand the difference between independent samples and matched pairs.
5. What are the assumptions associated with testing inferences about two means.
6. To explore the data sets, there are 4 things that the text states would be helpful, what are they?
7. What is the test statistic for large independent samples?
8. The example (Coke versus Pepsi) on page 440-1 is very informative.
9. The formula for confidence interval and a good example are given on page 442.
10. The differences between sample means tend to be __________ distributed.
11. The population standard deviation of the differences between the sample means is _______________. In other words, the variance of the differences between two independent random variables equals the variance of the first random variable _____ the variance of the second random variable.
12. The method used to compute this statistic using STATDISK is given on page 443.

 

Do the odd problems on pages 444-448.

 

13. What are the assumptions associated with testing samples with matched pairs?
14. In dealing with sample data consisting of matched pairs, the calculations are based on the ______________ ____________ the pairs of data.
15. What is the difference between the t-test statistic given on page 450 and the t-test statistic given on page 400?
16. The example on pages 451-2 concludes that male students exaggerate their heights by reporting values that are greater than their measured heights. What reasons can you give for this over-reporting?
17. If the outlier was not thrown out, it would have had the following effect on the test statistics: The mean of differences would be ____________ and the variance would be _______________.
18. In this example, the 0.05 level of significance was chosen by the researcher. Would the null hypothesis have been rejected if the 0.01 level of significance had been chosen?
19. The technique used to do the matched pairs analysis using STATDISK is given on page 453.

 

Do the odd problems on pages 454-458.

 

20. Note the calculation on page 459 that leads to the pooled estimate of the proportions.
21. The test statistic is given on page 460
22. Read through the example on page 460-463
23. Note the confidence interval calculation on page 463 and the example on pages 463-464.
24. Be sure to read and understand the RATIONALE on page 464
25. The technique used to perform these calculations using STATDISK are given on page 465.
26. Read the sidebar on Aspirin (page 464). What is your opinion? Should everyone take aspirin to avoid heart attacks? What are the disadvantages of taking aspirin each day? Is it acceptable to focus on one particular aspect of a drug and ignore the side effects?

 

Do the odd problems on pages 466-9.

 

27. What are the assumptions associated with the test that compares variation in two samples?
28. How is the F-statistic calculated?
29. What are the assumptions of the F distribution?
30. If the variances are equal then the ratio will be close to ____
31. Refer to the example on pages 473-475. This conclusion might make it appear that there is no significant difference between the population variances when there really is a difference that was hidden by _________ distributions.
32. The technique used to calculate the statistic using STATDISK is given on page 475

 

Work the odd problems on pages 476-479.

 

33. What are the assumptions for testing hypotheses of independent and small samples?
34. What are the three possible cases when applying this test?
35. What are the pro and con arguments for using the preliminary F test to determine if the variances of the two independent samples are equal?
36. What are the two schools of thought?
37. What is the test statistic for small independent samples with equal variances?
38. Read through the example on pages 481-483 and notice that the F test did not reject the hypothesis that both variances were equal.
39. How does the test statistic for unequal variances (page 484) compare with the test statistic for equal variances (page 481)?
40. Read through the example on pages 485-486.
41. The flowchart on page 487 will help to organize the thought process that the student can go through when attempting to determine which test is the best to use.
42. The procedure to be used with STATDISK is given on page 486.

 

Work the odd problems on pages 488-492.

 

Do the Review and Cumulative Review Exercises on pages 494-498.

 

MATH 1442 students need to do the following and email the answers to [email protected]:

• Answer the 5 questions in ‘The Fear of Flying’ (page 493)
• Work through the Critical Thinking exercise on page 500 and write a brief report as suggested
• Use STATDISK to analyze the data on page 481 as a Small Independent Sample and UNEQUAL variances (procedure on page 486). Compare your result with that obtained on page 483(t=--6.119). Which of the tests has the greatest power?

 

The Chapter 8 test will be available starting on __________ until ________. The test will consist of 17 multiple choice questions and has a time limit of 35 minutes. Students can use their textbook and notes when taking this test.