Question

For a binomial distribution mean is 6 and variance is 2. Find n and p.

Answer 1

Mean = 6, Variance = 2 But,

Mean = np and Variance = npq

∴ np = 6 and npq = 2

npq=2

(6)q=2   [∵ np=6]

q=1/3 ......(1)

p=1-1/3=2/3 [∵p=1-q]

`p=2/3`

np=6

n(2/3)=6

`n=9`