Elementary Statistics (12th Edition)

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

Chapter 5 - Discrete Probability Distributions - 5-4 Parameters for Binomial Distributions - Beyond the Basics - Page 228: 21


Standard deviation=6, p=0.4, n=150.

Work Step by Step

We know that the minimum and maximum usual values are 48 and 72, therefore the mean is 60 and the standard deviation is 6. We also know that standard deviation: 6=$\sqrt{n \cdot p \cdot (1-p)}=\sqrt{mean \cdot (1-p)}=\sqrt{60\cdot (1-p)}$, therefore 1-p=0.6, p=0.4. Mean=$n\cdot p$, therefore n=$\frac{mean}{p}=150$.
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.