Question

The sum of mean and variance of a binomial distribution is 15 and their product is 54 then the distribution is

• A. $n=27,p=\frac{1}{3},q=\frac{2}{3}$
• B. $n=20,p=\frac{1}{3},q=\frac{2}{3}$
• C. $n=15,p=\frac{2}{3},q=\frac{1}{3}$
• D. $n=18,p=\frac{2}{3},q=\frac{1}{3}$

Answer 1

The correct option is A $n=27,p=\frac{1}{3},q=\frac{2}{3}$

np + npq = 15 and np (npq)= 15
By verification $n=27,p=\frac{1}{3},q=\frac{2}{3}$