Question

Consider the following binomial experiment: a study in a certain community showed that 6% of the people suffer from insomnia. if there are 10,200 people in this community, what is the standard deviation of the number of people who suffer from insomnia?

Answer 1

To determine the standard deviation of the number of people who suffer from insomnia, you need to use the following formula:
= sqr of npq

= √10,200 people in the community x 0.6 people who suffer from insomnia x 0.91 = ?
= √10,200 x 0.6 x 0.91 = √55.143 = 7.43 

= 7.43