A couple plans to have children until they get a boy,but they agree that they will not have more than four children even if all are girls.Find the expected number of children they will have.Assume that boys and girls are equally likely.Round your answer to three decimal places.
A)1.625
B)1.750
C)2.500
D)1.938
E)1.875

Question

Quizplus · Accepted Answer

The expected number of children is calculated by considering the probabilities of having a boy in the first, second, third, or fourth child. The expected value is 1*(1/2) + 2*(1/4) + 3*(1/8) + 4*(1/16) + 4*(1/16) = 1.875.

A Couple Plans to Have Children Until They Get a Boy,but