Question

If for a $BD$ the mean is 6 and standard deviation is $\frac{1}{\sqrt{2}},$ the probability of success is

• A. $\frac{11}{12}$
• B. $\frac{10}{12}$
• C. $\frac{9}{12}$
• D. $\frac{8}{12}$

Answer 1

Answer: (A)

$\frac{11}{12}$

Let the parameters of the binomial distribution be $(n,p)$ where $n$ is number of trials

$p$ is probability of success. Therefore, we have

Mean $=np=6$

Variance $=(\frac{1}{\sqrt{2}}{)}^2=\frac{1}{2}$

Variance $=np(1-p)=\frac{1}{2}.$

$1-p=\frac{1}{12}$

$p=\frac{11}{12}.$