Question

Twenty percent of the students in a class of 100 are planning to go to graduate school. The standard deviation of this binomial distribution is

Answer 1

Answer: 4

Step-by-step explanation:

For any binomial variable X having parameters n (total number of trials ) and p (probability of getting success in each event), the standard deviation is given by :-

$\sigma=\sqrt{np(1-p)}$

As per given , we have

n= 100 , p= 20%=0.20

Then, the standard deviation of this binomial distribution is :

$\sigma=\sqrt{100(0.20)(1-0.20)}\\\\=\sqrt{100(0.16)}=4$

Hence, the  standard deviation of this binomial distribution is 4.