A 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 waiting
Time was found to be a variable best approximated by an exponential distribution with a mean
Length of waiting time equal to 3 minutes (i.e. the mean number of calls answered in a minute is
1/3). Find the waiting time at which only 10% of the customers will continue to hold.
A) 2.3 minutes
B) 3.3 minutes
C) 6.9 minutes
D) 13.8 minutes

Question

Quizplus · Accepted Answer

The exponential distribution's cumulative distribution function (CDF) is used to find the waiting time. For 10% of customers to continue holding, we solve for t in 1 - e^(-t/3) = 0.10, which gives t ≈ 6.9 minutes.

A Company That Receives the Majority of Its Orders by Telephone