Elementary Statistics (12th Edition)

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

Chapter 9 - Inferences from Two Samples - 9-4 Two Dependent Samples (Matched Pairs) - Basic Skills and Concepts: 19

Answer

$\mu_d$ is between 0.691 and 5.559.

Work Step by Step

The corresponding critical value using the table with df=8-1=7: $t_{\alpha/2}=t_{0.025}=2.365.$ The margin of error: $E=t_{\alpha/2}\frac{s_d}{\sqrt{n}}=2.365\frac{2.9114}{\sqrt{8}}=2.434.$ Hence the confidence interval $\mu_d$ is between $\overline{d}-E$=3.125-2.434=0.691 and $\overline{d}+E$=3.125+2.434=5.559. The interval doesn't contain 0, so it seems to be effective.
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.