# What is the standard deviation of a binomial distribution with n=10 and p=0.70?

Oct 27, 2015

$1.449$

#### Explanation:

Variance $= n p \left(1 - p\right) = 10 \cdot 0.7 \cdot 0.3 = 2.1$
So standard deviation $= \sqrt{2.1} = 1.449$