Quiz 7 in Math 243: Hypothesis Testing and Cheating Probabilities, Quizzes of Probability and Statistics

Download Quiz 7 in Math 243: Hypothesis Testing and Cheating Probabilities and more Quizzes Probability and Statistics in PDF only on Docsity! Quiz 7 Name Math 243 GTF May 22, 2009 Disc. Time 1. On a certain 6th grade math test, it is suspected that females will score higher than males. A simple random sample of 21 6th graders, 11 male and 10 female, from around the country are given the math test. The scores are given below: Male 47 55 60 63 71 72 74 75 81 81 82 Female 58 59 59 71 72 72 77 84 87 96 Is there significant evidence at the α = 0.02 level that females perform better on the test than males? You may assume that the appropriate test is safe to use. Be sure to state your conclusion in language appropriate to the context of the problem. Do not just fill in the blanks; you will be graded on showing the appropriate work. Hypotheses: Let µ1 be the mean score of all 6th grade females. Let µ2 be the mean score of all 6th grade males. H0 : µ1 = µ2 Ha : µ1 > µ2 Test statistic: t ≈ 0.80828 P -value (or range of values for P ): P ≈ 0.21467 or 0.2 < P < 0.25 Conclusion: Since P > α there is not sufficient evidence to reject the null hypothesis. There is not good evidence that 6th grade females perform better than 6th grade males on this math test. 2. In a math 243 class, the probability that a cheater will get caught is 1/5. Which of the following is true? (a) If 5 people cheat, exactly one will get caught. (b) If 5 people cheat, at least one will get caught. (c) If 5 people cheat, at most one will get caught. (d) If 6 people cheat, at least one will get caught. (e) If one person cheats 5 times, they will get caught at least once. (f) If the whole class cheats, 1/5 of the class will get caught. (g) If many people cheat, the proportion that will get caught will be close to 1/5. (h) If a person cheats 4 times and doesn’t get caught, he/she is more likely to get caught the fifth time he/she cheats. (i) None of the above.