Question

In binomial probability distribution, mean is 3 and standard deviation $\frac{3}{2}$is

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Mean = np = 3, S.D = $\sqrt{npq}=\frac{3}{2}$
$\Rightarrow q=\frac{npq}{np}=\frac{9}{4\times 3}=\frac{3}{4}$ $\Rightarrow p=1-\frac{3}{4}=\frac{1}{4}$
Hence binomial distribution is $(q+p{)}^n$ = ${(\frac{3}{4}+\frac{1}{4})}^{12}$