A group of college DJs surveyed students to find out what music to plan for their upcoming parties. Thirty percent of the students preferred dubstep, 25% of the students liked trance music, and 20% wanted to hear only house music. Fifteen percent of the respondents selected both dubstep and trance. The conditional probability that a student likes dubstep, given that he or she likes trance music, is:
A)55%.
B)60%.
C)65%.
D)70%.

Question

Quizplus · Accepted Answer

The conditional probability that a student likes dubstep given they like trance is calculated by dividing the percentage of students who like both dubstep and trance (15%) by the percentage of students who like trance (25%). This gives 15%/25% = 0.6 or 60%.

A Group of College DJs Surveyed Students to Find Out