A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs,...
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A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two model were taken. Analysis of 11 bulbs of mnodel A showed a mean lifetime of 1227 hours and a standard deviation of 86 hours. AnalysSis of 15 bulbs of model B showed a mean lifetime of 1379 hours and a standard deviation of 91 hours. Assume that the populations of lifetimes for each model are normally distributed and that the variances of these populations are equal. Construct a 95% confidence interval for the difference u,-ul, between the mean lifetime u, of model A bulbs and the mean lifetime u, of model B bulbs. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.) - 220.5 What is the lower limit of the 95% confidence interval? -83.42 What is the upper limit of the 95% confidence interval? A light bulb manufacturer wants to compare the mean lifetimes of two of its light bulbs, model A and model B. Independent random samples of the two model were taken. Analysis of 11 bulbs of mnodel A showed a mean lifetime of 1227 hours and a standard deviation of 86 hours. AnalysSis of 15 bulbs of model B showed a mean lifetime of 1379 hours and a standard deviation of 91 hours. Assume that the populations of lifetimes for each model are normally distributed and that the variances of these populations are equal. Construct a 95% confidence interval for the difference u,-ul, between the mean lifetime u, of model A bulbs and the mean lifetime u, of model B bulbs. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your responses to at least two decimal places. (If necessary, consult a list of formulas.) - 220.5 What is the lower limit of the 95% confidence interval? -83.42 What is the upper limit of the 95% confidence interval?
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Related Book For
Statistics for Business and Economics
ISBN: 978-0132930192
8th edition
Authors: Paul Newbold, William Carlson, Betty Thorne
Posted Date:
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