Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

P. 3.7 Suppose that a birth is equally likely to be a boy or girl, and the outco

ID: 3351566 • Letter: P

Question

P. 3.7 Suppose that a birth is equally likely to be a boy or girl, and the outcome of one birth does not change this probability for future births a. Describe how you could use a coin to approximate the probability that a couple with four children would have two boys and two girls b. It turns out that the probability is 0.375 that a couple with four children would have two boys and two girls. Interpret what this probability means c. Based on the probability given in part (b), what is the probability that a couple with four children does not have two boys and two girls?

Explanation / Answer

A) Take a coin, toss it 4 times and note down the number of heads. Let the number of heads be 'k'

Repeat this experiment n times, say n = 20

Count the number of times k = 2 (2 heads)

k/n is the approximate probability that a couple with four children would have two boys and two girls

B) The probability of 0.375 indicates that, for every couple with 4 children, there is 0.375 (37.5%) chance that there will be two boys and two girls. Or, in every 1000 couples with 4 children, we expect 375 couples to have 2 boys and 2 girls.

C) Probability that a couple with four children do not have 2 boys and 2 girls = 1 - 0.375

= 0.625