If the mean and variance of a binomial variate X are 2 and 1 respectively, find P(X > 1).
Given:
Mean= 2
Variance=1
P(x>1)=?
P(x>1)=1-p(x1)
= 1-[p(x=0)+p(x=1)]
=1-[ 11qn +npqn-1]
2(1-p)=1
=q
np=2
n=4