Unformatted text preview: STA 3024 Assignment 2: Form 0 Suppose we want to investigate the gateway drug theory—the idea that marijuana use can lead to use of more serious drugs, such as cocaine and heroin. We distribute an anonymous questionnaire to a random sample of 164 high school students that asks whether they have ever used marijuana and whether they have ever used cocaine or heroin. Our results are summarized by the following contingency table: Cocaine/Heroin Marijuana Yes No Total Yes 8 56 64 No 7 93 100 Total 15 149 164 This form is only for people whose UFID number starts with 0. 1. For our sample data, calculate the conditional distribution of whether or not students have used cocaine/heroin, given whether or not they have used marijuana. (Your answer should be a 2 × 2 table of conditional percentages.) 2. Now let’s use this data to conduct a chisquared test with α = 0 . 05. (a) Calculate each cell’s expected count for the chisquared test. (Your answer should be a 2 × 2 table of expected counts.)2 table of expected counts....
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 Spring '08
 TA
 Statistics, Normal Distribution, Pearson's chisquare test, Fisher's method

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