Independent solution

How to solve this Bayes' Theorem question

Setup

Setup

Complement the supplied female rate within committee Y and the committee-Y marginal.

Pr(MY)=10.40=0.60\Pr(M\mid Y)=1-0.40=0.60
Pr(X)=10.60=0.40\Pr(X)=1-0.60=0.40

Model

Model

Compute the male contributions from the two committees.

Pr(MY)=0.60(0.60)=0.36\Pr(M\cap Y)=0.60(0.60)=0.36
Pr(MX)=0.30(0.40)=0.12\Pr(M\cap X)=0.30(0.40)=0.12

Compute

Compute

Normalize committee Y's contribution by the total male probability.

Pr(M)=0.36+0.12=0.48\Pr(M)=0.36+0.12=0.48
Pr(YM)=0.360.48=0.75\Pr(Y\mid M)=\frac{0.36}{0.48}=0.75

Answer

Answer

Given that the person is male, the probability of committee Y is 0.75.

0.75(E)\boxed{0.75\quad\text{(E)}}