ex2_6126sol

# ex2_6126sol - STA 6126 Exam 2 1 Based on responses of 1600...

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STA 6126 Exam 2 1. Based on responses of 1600 subjects in General Social Surveys in the mid-1980s, a 95% Confidence Interval for the mean number of close friends equals (5.6, 7.2). For each statement, circle the best response: Correct or Incorrect . a) If random samples of 1600 were repeatedly selected and 95% Confidence intervals computed based on each sample, then in the long run 95% of the intervals would contain the true mean. Correct b) We can be 95% confident that Y is between 5.6 and 7.2. Incorrect c) 95% of respondents had between 5.6 and 7.2 close friends. Incorrect d) We can be 95% confident that \mu is between 5.6 and 7.2. Correct 2. The P -value for testing H 0 : \mu=100 vs H A : \mu 100 is 0.001 and 100 < Y . This indicates strong evidence that (select the correct answer): a) \mu<100 b) \mu>100 c) \mu=100 3. A large-sample 95% confidence interval for \mu_1-\mu_2 is (-2.0, 7.0). The P -value for testing H 0 : \mu_1-\mu_2=0 vs H A : \mu_1-\mu_2 0 based on the same sample data is (select the correct answer): a) above 0.05 b) below –0.05 c) below 0.05 d) Need more information 4. Researchers reporting a Z-test to test the alterntative hypothesis that the proportion of males favoring a candidate is larger than the proportion of females favoring the candidate (H A :\mu_ M -\mu_ F > 0) give a P -value of 0.0643. Their computed test statistic was: a) 0.0643 b) 1.52 c) 1.85 d) 0.9357 e) We need more information

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For each of the following problems, give the null and alternative hypotheses (be very careful in notation with respect to symbols and subscripts) 5. Researchers believe that when faced with the question: “Do you have a favorable attitude toward President Bush”?, men are more likely to respond “Yes” than women. Ho: p_male-p_female≤0
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ex2_6126sol - STA 6126 Exam 2 1 Based on responses of 1600...

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