Okay here is the question and below it is my attempt to solve it.
1.4 Suppose that the probability that both of a pair of twins are boys is
0.30 and that the probability that they are both girls is 0.26. Given
that the probability of the first child being a boy is 0.52, what is the
probability that the second twin is a boy, given that the first is a boy?
I tried to use bayes theorem as follows.
P(b1)=.52
P(b1|b2)=.3
P(b2)=??
P(b2|b1)=??
P(b2|b1)= (.3*.5)/.52
The correct answer is listed as P(b2|b1)=15/26 =.5777
why did they multiply .52 by .5????
1.4 Suppose that the probability that both of a pair of twins are boys is
0.30 and that the probability that they are both girls is 0.26. Given
that the probability of the first child being a boy is 0.52, what is the
probability that the second twin is a boy, given that the first is a boy?
I tried to use bayes theorem as follows.
P(b1)=.52
P(b1|b2)=.3
P(b2)=??
P(b2|b1)=??
P(b2|b1)= (.3*.5)/.52
The correct answer is listed as P(b2|b1)=15/26 =.5777
why did they multiply .52 by .5????