A catalog company that receives the majority of its orders by telephone conducted a study to determine how long customers were willing to wait on hold before ordering a product. The length of time was found to be a random variable best approximated by an exponential distribution with a mean equal to 2.8 minutes. What is the probability that a randomly selected caller is placed on hold fewer than 7 minutes?
A) 0.082085
B) 0.9990881
C) 0.0009119
D) 0.917915

Question

Quizplus · Accepted Answer

The exponential distribution with a mean of 2.8 minutes has a rate parameter λ = 1/2.8. The probability that a caller is on hold for fewer than 7 minutes is given by 1 - e^(-7/2.8), which is approximately 0.917915.

A Catalog Company That Receives the Majority of Its Orders