An important part of the customer service responsibilities of a cable company relates to the speed with which trouble in service can be repaired.Historically,the data show that the likelihood is 0.75 that troubles in a residential service can be repaired on the same day.For the first five troubles reported on a given day,what is the probability that at least three troubles will be repaired on the same day?
A).1035
B).0376
C).9624
D).8965

Question

Quizplus · Accepted Answer

The probability of at least three troubles being repaired on the same day can be calculated using the binomial probability formula. The probability of 3, 4, or 5 repairs is calculated and summed: P(X ≥ 3) = P(X=3) + P(X=4) + P(X=5) = 0.2637 + 0.3955 + 0.2373 = 0.8965.

An Important Part of the Customer Service Responsibilities of a Cable