assign1 - (c) Based on your analyses is it reasonable to...

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Assignment Categorical Data Analysis, CHL 5407H DUE DATE: January 28, 2003 1. You are asked to design a cross-sectional study investigating the exercise habits of new graduate students at the University of Toronto. Students will be classiFed as being inactive if they exercise less than twice a week while students who exercise at least twice a week are classiFed as being active. How many students would have to be enrolled to ensure that a 90% conFdence interval about the estimated proportion of students being active is no wider than ± 0 . 05? 2. Data on smoking history from four studies of lung cancer patients are provided in Table 1. Use these data to answer the following questions. (a) Construct an hypothesis test using these data to test the null hypothesis that the true proportion of smokers does not vary across the four studies. Provide a brief explanation of your results. (b) Use SAS to obtain the same results.
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Unformatted text preview: (c) Based on your analyses is it reasonable to summarize the results from these four studies by noting that 94% (= 100% × 372 / 397) of lung cancer patients are smokers? Provide a brief explanation supporting your answer. Table 1. Smoking status among lung cancer patients in four studies Number of Number of Study Patients Smokers 1 86 83 2 93 90 3 136 129 4 82 70--------------------------------Overall 397 372 3. A study investigated the relationship between the use of oral contraceptives and the development of endometrial cancer. It was found that of 117 endometrial-cancer patients, 6 had used the oral contraceptives Oracon, at some time in their lives, whereas of 395 controls, 8 had used this agent. Can we conclude from these data that women using Oracon are at an increased risk of endometrial cancer? Provide a brief justiFcation for your answer. 1...
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This note was uploaded on 11/20/2011 for the course STATISTICS ST3241 taught by Professor Manwai's during the Spring '11 term at National University of Singapore.

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