Question

A random sample of n people selected from a large population will be asked whether they have read a novel in the past year. Let the random variable R represent the number of people from the sample who answer yes. The variance of random variable R is 6. Assume the responses are independent of each other. If the proportion of people from the population who read a novel in the past year is 0.40, which of the following is the best interpretation of random variable R ?a. binomial variable with 15 independent trialsb. A binomial variable with 25 independent trialsc. A variable that is not binomial with 25 independent trialsd. A binomial variable with 40 independent trialse. A variable that is not binomial with 40 independent trials

Answer 1

Answer:

b. A binomial variable with 25 independent trials

Step-by-step explanation:

The conducted experiment is binomial experiment because outcome can be divided into success or failure. The success would be the people who read novel in the past year and also responses are independent of each other. We have to find the number of trials n in the given problem.

we are given that variance of R=6 and p=probability of success=0.4.

We know that variance of binomial distribution is

Variance=npq

where q=1-p=1-0.4=0.6.

By putting the values in variance formula, we can get the value of n.

6=n*0.4*0.6

6=0.24*n

n=6/0.24

n=25

Hence, random variable R is a binomial variable with 25 independent trials.