# What are the mean and standard deviation of a binomial probability distribution with n=15  and p=3/7 ?

Jan 11, 2016

Mean $= 6.43$
SD $= 1.92$

#### Explanation:

Given-

$n = 15$
$p = \frac{3}{7}$

Calculate -

$q = 1 - p = 1 - \frac{3}{7} = \frac{4}{7}$

$M e a n = n p = 15 \times \frac{3}{7} = 6.43$
$S D = \sqrt{n p q} = \sqrt{15 \times \frac{3}{7} \times \frac{4}{7}} = \sqrt{36.7} = 1.92$