Question

If a distribution follows the binomial distribution with n = 40 and probability of success of 0.35, calculate the mean and variance

A. Mean = 14, Variance = 9.1
B. Mean = 20, Variance = 3.9
C. Mean = 26, Variance = 16.9
D. Mean = 40, Variance = 0.35​

Answer 1

mean=14, variance=9.1

Explanation:

for binomial distribution

n=number of outcomes

p=probability of succcess

q=probability of faliure

p+q=1

any probability given is always 'p'

mean=np

n=40

p=0.35

mean=40*0.35

mean=14

variance=npq

p+q=1

q=1-p

q=1-0.35

q=0.65

variance=40*0.35*0.65

variance=9.1