# What are the mean and standard deviation of a binomial probability distribution with n=10  and p=4/5 ?

Apr 4, 2016

Mean $= 8$
SD$= 1.265$

#### Explanation:

Mean $= n p = 10 \times \frac{4}{5} = 8$
SD $= \sqrt{n p q}$

$q = 1 - p = 1 - \frac{4}{5} = \frac{1}{5}$
SD $= \sqrt{10 \times \frac{4}{5} \times \frac{1}{5}} = 1.265$