# What are the mean and standard deviation of a binomial probability distribution with n=25  and p=11/17 ?

##### 1 Answer
Feb 18, 2016

The mean of X is u = np
The standard deviation of X is $\sum = \sqrt{n p \left(1 - p\right)}$

#### Explanation:

If X has a binomial distribution with n trials and probability of success p on each trial, then:

1. The mean of X is u = np
2. The variance of X is ${\left(\sum\right)}^{2} = n p \left(1 - p\right)$
3. The standard deviation of X is $\sum = \sqrt{n p \left(1 - p\right)}$

Retrieved from:
By Deborah J. Rumsey from Statistics For Dummies, 2nd Edition
http://www.dummies.com/how-to/content/how-to-find-the-mean-variance-and-standard-deviati.html