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Unformatted text preview: Stat131a Dr. Wong Practice Midterm February 27, 2003 Spring Semester 2004 UC Berkeley This exam has 20 questions, for a total of 110 points. Your answers to multiple choice ques- tions should appear on the first page of your bluebooks. For non-multiple choice questions, show any formulas and some intermediate calculations in your bluebooks, not just your final answer. Designing a Study Questions 1 through 3 concern this situation: Want to stop smoking? Nicotine patches may help, and so may taking a drug that fights depression. A report in a recent issue of the New England Journal of Medicine describes a study of what works best. Here is part of the summary: Use of nicotine replacement therapies and the antidepressant bupropion helps people stop smoking. We conducted a double-blind, placebo-controlled comparison of sustained-release bupropion (244 subjects), a nicotine patch (244 subjects), bupropion and a nicotine patch (245 subjects), and placebo (160 subjects) for smoking cessation. Results . The abstinence rates at 12 months were 15.6% in the placebo group, as compared with 16.4% in the nicotine patch group, 30.3% in the bupropion group, and 35.5% in the group given bupropion and the nicotine patch. 1. 5 Pts How many treatments did this experiment compare? (a) two (b) three (c) four (d) can’t tell from the information given answer (c) Four treatments: placebo; nicotine patch; bupropion; and bupropion plus nicotine patch 2. 5 Pts The response variable in this experiment is (a) the combination of drug (bupropion or placebo) and nicotine patch (b) 893 people who want to quit smoking (c) bupropion (d) whether or not a subject was able to abstain from smoking for a year. answer (d) stop smoking or not 3. 5 Pts One group received a placebo. Why not just give this group no treatment at all? (a) It is not ethical to give no treatment at all in this setting. (b) Just thinking you are getting a treatment may have an effect, and we want to see if the real treatments do better than this. (c) A placebo is the same thing as no treatment at all. (d) Subjects would be disappointed if not given a pill. answer (b) Placebo measures the demonstrated effect of a subject’s belief, even without any other trt Page 1 of 6 Continue on next page ... Stat131a Dr. Wong Practice Midterm February 27, 2003 Spring Semester 2004 UC Berkeley 4. 5 Pts For a simple random sample of size 10,881, the conservative margin of error for 95% confidence is about (a) ± 9 . 6% (b) ± 3% (c) ± . 96% (d) ± . 0096% answer (c) ± . 96% 5. 5 Pts A study of the effect of government job training programs finds that the pay of workers after...
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- Spring '08
- Statistics, pts, Smoking cessation, Stat131a Dr. Wong