# Thread: Probability problem

1. ## Probability problem

suppose candidate A receives 54% of the entire vote, but only 48% of the female vote. A voter is selected at random for an interview. What is the probability that the voter is a woman who voted for candidate A?

2. Originally Posted by ragger33
suppose candidate A receives 54% of the entire vote, but only 48% of the female vote. A voter is selected at random for an interview. What is the probability that the voter is a woman who voted for candidate A?
You can write a formula involving the population of voters.

$P=\frac{0.48W}{M+W}=\frac{0.48(0.54)W}{M_A+W_A}$

where the subscript "A" indicates those who voted for Candidate A.

$\frac{M_A+W_A}{M+W}=0.54$

$\frac{W_A}{W}=0.48$

$\frac{0.48W}{W+M}=0.48W\frac{0.54}{M_A+W_A}
$

Different populations of men and women give different results..

For instance, if there were 100 men and 100 women

$\frac{48}{100}+\frac{M_A}{100}=\frac{48+M_A}{200}= \frac{54}{100}=\frac{108}{200}$

then $M_A=60$

but

$\frac{0.48W}{W+M}=\frac{48}{200}=P$

If we change the number of men, the probability will change.
If we change the number of women, the probability will change.