What is the variance of a binomial distribution for which n = 75 and p = 0.20?

2 Answers
Nov 1, 2015

75 x (15) x (45)

Explanation:

The formula for the variance of a binomial distribution is n x p x q where q = 1 - p. Here n = 75, p = .20 or (15) and q = 0.80 or (45) and hence the answer.

Nov 1, 2015

The answer is 12.

Explanation:

Note that if X~Bin ( n , p ) then Variance of X is np(1p).

Now your n=75 and p=0.20.

So your variance = 75×0.20×(10.20)=75×0.20×0.80=12