MATH 225N Week 6 quiz (2020)| MATH 225 Week 6 Statistics 2020
MATH 225N Week 6 quiz (2020) – Chamberlain College of Nursing QUESTION 1 · 1/1 POINTS A statistics professor recently graded final exams for students in her introductory statistics course. In a review of her grading, she found the mean score out of points was a x¯=77x¯=77, with a margin of error of 10.10. Construct a confidence interval for the mean score (out of points) on the final exam. Answer Explanation Correct answers: A confidence interval is an interval of values, centered on a point estimate, of the form (pointestimate−marginof error,pointestimate+marginof error) (pointestimate−marginof error,pointestimate+marginof error) Using the given point estimate for the mean, x¯=77x¯=77 and margin of error 1010, the confidence interval is: (77−10,77+10)(67,87)(77−10,77+10)(67,87) FEEDBACK • • • • Content attribution- Opens a dialog • $left(67, 87right)$(67, 87) That is correct! $$(67, 87) That is correct! QUESTION 2 · 1/1 POINTS A random sample of adults were asked whether they prefer reading an e-book over a printed book. The survey resulted in a sample proportion of p′=0.14p′=0.14, with a sampling standard deviation of σp′=0.02σp′=0.02, who preferred reading an e-book. Use the empirical rule to construct a 95%95% confidence interval for the true proportion of adults who prefer e-books. Answer Explanation Correct answers: By the Empirical Rule, a 95%95% confidence interval corresponds to a zz-score of z=2z=2. Substituting the given values p′=0.14p′=0.14 and σp′=0.02σp ′=0.02, a confidence interval is (p′−z⋅σp′,p′+z⋅σp′)(0.14−2⋅0.02,0.14+2⋅0.02) (0.14−0.04,0.14+0.04)(0.10,0.18)(p′−z⋅σp′,p′+z⋅σp′) (0.14−2⋅0.02,0.14+2⋅0.02)(0.14−0.04,0.14+0.04)(0.10,0.18) FEEDBACK • • • • Content attribution- Opens a dialog QUESTION 3 · 1/1 POINTS The pages per book in a library are normally distributed with an unknown population mean. A random sample of books is taken and results in a 95%95% confidence interval of (237,293)(237,293) pages. What is the correct interpretation of the 95%95% confidence interval? • $left(0.10, 0.18right)$(0.10, 0.18) That is correct! $$(0.10, 0.18) That is correct! $$14 dog heights We estimate with 95%95% confidence that the sample mean is between and pages. We estimate that 95%95% of the time a book is selected, there will be between and pages. We estimate with 95%95% confidence that the true population mean is between and pages. Answer Explanation Correct answer: Once a confidence interval is
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