Interpreting Conditional Probability 2

Question

If 21% of males and 15% of females in a given state play the guitar, what is the probability that a randomly selected subject in the state plays the guitar, given that the subject is male?

A. 

0.15

B. 

0.21

C. 

0.79

D. 

0.85

Answer 1

Using the definition of conditional probability (i.e. P(A|B) = P(A∩B)/P(B) )

we have

P(randomly selected subject plays the guitar | the subject is male ) =

P(the subject is male and plays the guitar) / P(the subject is male) =

((0.21)*(0.50)) / (0.50) =

0.21

Thus, (B) is the correct answer