Homework #1 - Due Friday, 9/14/2007

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Please answer clearly, in full sentences, on one side only of your own paper, leaving plenty of space for remarks by the graders. Staple your pages if you can. You may collaborate with others in and out of the class, but you must prepare your own answers. Papers are due at the start of class on Friday.

A. In chapter 1, do problems 1.8, 1.10, 1.12, 1.14.

B. In chapter 2:

Consider problem 2.10 (p. 30, about male and female faculty).
   a. Explain why this sampling method gives each member of the faculty an equal chance to be chosen.
   b. Nonetheless, this is not an SRS. Why not?
   c. Is it better than an SRS? Or worse? Explain any advantages or disadvantages you can see.

Consider problem 2.15 (p. 31, about phone surveys). Is this really a good idea? Does it raise other problems? What are the "selection bias" problems here? (Just to be specific, imagine that the surveyor is trying to find out what fraction of adults in the telephone exchange are married, and the survey question is "are you married?")

C. In chapter 3:

In problems 3.1 through 3.4, identify each boldface number as a parameter or a statistic, and also identify each as a population average, population proportion, sample average, or sample proportion.

Also do problems 3.9, 3.13, 3.14, 3.15, 3.19, 3.26.

D. In chapter 4, do problems 4.4, 4.10, 4.21.