Fiesta 3
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Fiesta 3 as PDF for free.
More details
- Words: 290
- Pages: 1
AP Statistics | Winter 2009 | Fiesta #3 | Shubleka
Problem 1 To determine whether the mean nicotine content of a brand of cigarettes is greater than the advertised value of 1.4 milligrams, a health advocacy group tests H 0 : μ = 1.4 versus H a : μ > 1.4 . The calculated value of the test statistic is z = 2.42. a) Is the result significant at the 5% level? Why or why not? b) Is the result significant at the 1% level? Why or why not? c) What decision would you make about the null hypothesis in part a)? Part b)? Explain. Problem 2 We suspect that students will generally score higher the second time they take the SAT Mathematics exam than on their first attempt. Suppose we know that the changes in score (second try minus first try) have population standard deviation of σ = 50 . Here are the results for 46 randomly chosen high school students: -30 24 47 70 -62 55 -41 -32 128 -11 -43 122 -10 56 32 -30 -28 -19 1 17 57 -14 -58 77 27 -33 51 17 -67 29 94 -11 2 12 -53 -49 49 8 -24 96 120 2 -33 -2 -39 99 a) Construct graphical displays and calculate the numerical summaries for these data. Write a few sentences about the distribution of changes in SAT Math scores. b) Based on your work in part (a), do you believe that the population of differences in SAT Math score is Normally distributed? Why or why not? c) Do these data give good evidence that the mean change in the population is greater than 0? (Perform a significance test following the steps you have learned in class.)
Problem 1 To determine whether the mean nicotine content of a brand of cigarettes is greater than the advertised value of 1.4 milligrams, a health advocacy group tests H 0 : μ = 1.4 versus H a : μ > 1.4 . The calculated value of the test statistic is z = 2.42. a) Is the result significant at the 5% level? Why or why not? b) Is the result significant at the 1% level? Why or why not? c) What decision would you make about the null hypothesis in part a)? Part b)? Explain. Problem 2 We suspect that students will generally score higher the second time they take the SAT Mathematics exam than on their first attempt. Suppose we know that the changes in score (second try minus first try) have population standard deviation of σ = 50 . Here are the results for 46 randomly chosen high school students: -30 24 47 70 -62 55 -41 -32 128 -11 -43 122 -10 56 32 -30 -28 -19 1 17 57 -14 -58 77 27 -33 51 17 -67 29 94 -11 2 12 -53 -49 49 8 -24 96 120 2 -33 -2 -39 99 a) Construct graphical displays and calculate the numerical summaries for these data. Write a few sentences about the distribution of changes in SAT Math scores. b) Based on your work in part (a), do you believe that the population of differences in SAT Math score is Normally distributed? Why or why not? c) Do these data give good evidence that the mean change in the population is greater than 0? (Perform a significance test following the steps you have learned in class.)
