Q. In a binomial distribution the mean is 15 and variance is 10. Then parameter $n$ is
A) 28
B) 16
C) 45
D) 25
Explanation
(c)
Given mean, $np = 15$
and variance $np(1 - P) = 10$
$\therefore\ 1 - p = \frac{10}{15} = \frac{2}{3}\ \Rightarrow p = \frac{1}{3}$
$\therefore\ n = 15 \times 3 = 45$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.