Chapter 11: Problem 2
Find the value of \(\chi^{2}\) for 12 degrees of freedom and an area of \(.025\) in the right tail of the chi-square distribution curve.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 11: Problem 2
Find the value of \(\chi^{2}\) for 12 degrees of freedom and an area of \(.025\) in the right tail of the chi-square distribution curve.
All the tools & learning materials you need for study success - in one app.
Get started for free
The October 2011 ISACA Shopping on the Job Survey asked employees, "During the holiday season (November and December), how much total time do you think an average employee at your enterprise spends shopping online using a work- supplied computer or smartphone?" Among those who responded, \(3 \%\) said 0 hours, \(24 \%\) said 1 to 2 hours, \(22 \%\) said 3 to 5 hours, and \(51 \%\) said 6 or more hours (www.isaca. org/SiteCollectionDocuments/2011-ISACA-Shopping- on-the-Job-Survey-US.pdf). Suppose that another poll conducted recently asked the same question of 215 randomly selected business executives, which produced the frequencies listed in the following table. $$ \begin{array}{l|cccc} \hline \text { Response/category } & 0 \text { hours } & 1-2 \text { hours } & 3-5 \text { hours } & 6 \text { or more hours } \\ \hline \text { Frequency } & 2 & 41 & 55 & 117 \\ \hline \end{array} $$ Test at a \(2.5 \%\) significance level whether the distribution of responses for the executive survey differs from that of October 2011 survey of employees.
Determine the value of \(\chi^{2}\) for 13 degrees of freedom and a. 025 area in the left tail of the chi-square distribution curve b. \(.995\) area in the right tail of the chi-square distribution curve
A sample of 30 observations selected from a normally distributed population produced a sample variance of \(5.8\). a. Write the null and alternative hypotheses to test whether the population variance is different from \(6.0\) b. Using \(\alpha=.05\), find the critical value of \(\chi^{2} .\) Show the rejection and nonrejection regions on a chi-square distribution curve. c. Find the value of the test statistic \(\chi^{2}\). d. Using a \(5 \%\) significance level, will you reject the null hypothesis stated in part a?
Find the value of \(\chi^{2}\) for 28 degrees of freedom and an area of \(.05\) in the right tail of the chi-square distribution curve.
Construct the \(98 \%\) confidence intervals for the population variance and standard deviation for the following data, assuming that the respective populations are (approximately) normally distributed. $$ \text { a. } n=21, s^{2}=9.2 \quad \text { b. } n=17, s^{2}=1.7 $$
What do you think about this solution?
We value your feedback to improve our textbook solutions.