Playbill Magazine Reported That The Mean Annual Household Income Of Its Readers

Playbill magazine reported that the mean annual household income of its readers is$119,155 (Playbill, January 2006). Assume this estimate of the mean annual household incomeis based on a sample of 80 households, and, based on past studies, the populationstandard deviation is known to be σ $30,000.SELF testSELF testWEB fileNielsenWEB fileTaxReturnCH008.qxd 8/16/10 6:38 PM Page 311 Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.a. Develop a 90% confidence interval estimate of the population mean.b. Develop a 95% confidence interval estimate of the population mean.c. Develop a 99% confidence interval estimate of the population mean.d. Discuss what happens to the width of the confidence interval as the confidence levelis increased. Does this result seem reasonable? Explain

Posted in Uncategorized