Suppose that a high school marching band has 86 members. Of these 86 band members, 26 are seniors, 17 play the trumpet, and 4 are seniors who play the trumpet. What is the probability that a randomly selected band member is a senior given that he or she plays the trumpet

0.3023

Step-by-step explanation:

86 band members

26 are senior, 17 plays trumpet. If 4 are seniors and play trumpet, we solve this using the bayes theorem of conditional probability.

Probability of choosing band member that plays trumpet =17/86 = 2/43.

Probability of choosing a senior that plays trumpet = 4/26

Probability that a chosen member is a senior given that he plays trumpet = (2/43)/(4/26)

= 0.3023.