Find the binomial distribution for which the mean is 4 and variance 3.

Explanation

Given `np=4` and `npq=3`

`therefore {npq}/{np}=3/4`

`implies q=3/4` and `p=1/4` and `n=16`

Binomial distribution is `P(X=r)=^nC_rp^rq^{n-r}`

`P(X=15)=^16C_15(1/4)^{15}(13/4)^{16-15}`

`P(X=15) =3/4^{14}`