Wed April 12 assignment

I. Review any reading or exercises not yet discussed.

II. Read p. 580 - middle of p. 591.

Be sure to learn the technical vocabulary (in boldface). You may need to think about how the phrases joint distribution (p. 583) and marginal distribution (p. 584) really do have the same meaning as in probability.
Why do you think marginal distributions are called marginal distributions?
Note the italics and the example on p. 585. As simple as this may seem at first glance, a lot of students make mistakes in this type of problem because they don't pay enough attention to the little word (like "of") that make a big difference. This is connected with the comments in italics on p. 586.
Simpson's Paradox (pp. 588 - 590) is important.
Pay attention to the cautions on p. 590.

III. Do the following exercises to reinforce reading and for possible class discussion:

pp. 612 - 616, #9.1 - 9.3, 9.7, 9.15
A friend observed two basketball teams practicing, and reported that one team made 50% of their shots, while the other made only 40%. Would you be justified in concluding that the first team was better at making shots?

IV. Hand in: #7.118 (p. 527), #7.120 (p. 528), #7.122 (pp. 528 - 529)
Please note:

Be sure to read problems carefully and answer all questions asked.
See Problem 7.119 for some ideas on what to include in your analysis and report for Problem 7.120.
Added 4/9: The data for #1.120 are in the file ta01_009 in the Chapter 1 file of the textbook data files.
Added 4/9: In Problem 7.120 (b), to get the data divided into the two populations usig Minitab, first use the Sort command on the Manipulation menu. Enter all the columns in the original data set under "Sort columns," then under "Store sorted columns in," put in names of five new columns where you want the sorted datd to go. You might lable them obs2, gpa2, etc. Enter "concept" under "Sort by column" and click OK. Then you can copy and past the first and second halves of the data into new columns, labeled perphaps "gpalow," "gpahi,"etc. Be sure to double-check that you've done everything correcty; it's easy to make mistakes.
You will need the computer for some parts of this assignment.
Your grade on #7.120 will be based partly on the quality of your writing, especially clarity and organization.
Therefore, be sure to start early to allow enough time to do this assignment satisfactorily
Be sure to state clearly both your null and alternate hypothesis whenever you do a hypothesis test. Also, explain why you have chosen the alternative that you have chosen.