Forty-three percent of US teens have heard of a fax machine. You randomly select 12 US teens. Find the probability that the number of these selected teens that have heard of a fax machine is exactly six (first answer listed below). Find the probability that the number is more than 8 (second answer listed below). A. 0.784, 0.974
B. 0.200, 0.974
C. 0.784, 0.026
D. 0.200, 0.026

D. 0.200, 0.026

Step-by-step explanation:

For each teen, there are only two possible outcomes. Either they have a fax machine, or they do not. The probability of a teen having a fax machine is independent of other teens. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.

Forty-three percent of US teens have heard of a fax machine.

This means that

You randomly select 12 US teens.

This means that

Find the probability that the number of these selected teens that have heard of a fax machine is exactly six (first answer listed below).

This is . So

So the answer is either option B or D.

Find the probability that the number is more than 8

So the correct answer is given by option D.