Elementary Statistics (12th Edition)

Published by Pearson
ISBN 10: 0321836960
ISBN 13: 978-0-32183-696-0

Chapter 7 - Estimates and Sample Sizes - 7-4 Estimating a Population Standard Deviation or Variance - Beyond the Basics - Page 371: 23

Answer

82.072, 129.635, These values are really close to the actual values.

Work Step by Step

$\alpha=1-0.9=0.1.$ Then we find the critival chi-square values by the given formula:$X_{L}^2=\frac{1}{2}(-z_{\alpha/2}+\sqrt{2k-1})^2=\frac{1}{2}(-1.645+\sqrt{2\cdot105-1})^2=82.072.$ $X_{R}^2=\frac{1}{2}(z_{\alpha/2}+\sqrt{2k-1})^2=\frac{1}{2}(1.645+\sqrt{2\cdot105-1})^2=129.635.$ These values are really close to the actual values.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.