Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The mode of the binomial distribution for which mean and standard deviation are 10 and $ \sqrt{5} $ respectively, is

Bihar CECEBihar CECE 2014

Solution:

In a binomial distribution, mean, $ np=10 $ and variance, $ npq=5 $ $ \therefore $ $ 10\times q=5\Rightarrow q=\frac{1}{2} $ $ \Rightarrow $ $ p=1-q=1-\frac{1}{2}=\frac{1}{2} $ Let x be the mode. Then, $ np+q>x>np-q $ $ \Rightarrow $ $ 10+\frac{1}{2}>x>10-\frac{1}{2} $ $ \Rightarrow $ $ \frac{21}{2}>x>\frac{19}{2}\Rightarrow 9.5