3) Previous experience shows the variance of a given process to be 40. Process engineers are testing to determine whether this value has decreased. a) What is the appropriate null and alternate hypothesis to determine if the process variance has decreased? Ho:o² > 40 versus Ha:o² < 40 b) Choose a level of a. Use a = 0.05 for this problem. c) To test the hypothesis, the process engineers take a sample of 22 and record the variable of interest. The data appear in the Process2 worksheet of the Quiz 2 Review Problems data workbook on Moodle. Collect data and calculate necessary statistics to test the hypothesis. Variance 20.89 d) Sketch the sampling distribution. Include the critical value and test statistic Critical Value: x =11.59 S'(n-1) _ 20.89(22–1) o? Test Statistic: Xố =10.97 40 e) Draw a conclusion and report that in the problem context. Reject Ho, conclude the process variance has decreased. f) Calculate the p-value for the hypothesis test Using table in book: 0.025 < p-value= P(xev <10.97) < 0.05 Using Excel: p-value=0.0366 A 52 44 51 58 48 51 53 47 43 49 50 54 52 47 47 49 38 49 50 42 55 52

3) Previous experience shows the variance of a given process to be 40. Process engineers are testing to determine whether this value has decreased. a) What is the appropriate null and alternate hypothesis to determine if the process variance has decreased? Ho:o² > 40 versus Ha:o² < 40 b) Choose a level of a. Use a = 0.05 for this problem. c) To test the hypothesis, the process engineers take a sample of 22 and record the variable of interest. The data appear in the Process2 worksheet of the Quiz 2 Review Problems data workbook on Moodle. Collect data and calculate necessary statistics to test the hypothesis. Variance 20.89 d) Sketch the sampling distribution. Include the critical value and test statistic Critical Value: x =11.59 S'(n-1) _ 20.89(22–1) o? Test Statistic: Xố =10.97 40 e) Draw a conclusion and report that in the problem context. Reject Ho, conclude the process variance has decreased. f) Calculate the p-value for the hypothesis test Using table in book: 0.025 < p-value= P(xev <10.97) < 0.05 Using Excel: p-value=0.0366 A 52 44 51 58 48 51 53 47 43 49 50 54 52 47 47 49 38 49 50 42 55 52

Holt Mcdougal Larson Pre-algebra: Student Edition 2012

1st Edition

ISBN:9780547587776

Author:HOLT MCDOUGAL

Publisher:HOLT MCDOUGAL

Chapter11: Data Analysis And Probability

Section: Chapter Questions

Problem 8CR

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