The average time between phone calls arriving at a call centre is 30 seconds.Assuming that the time between calls is exponentially distributed, find the probability that more than a minute elapses between calls.
A)0.135
B)0.368
C)0.865
D)0.607
E)0.709

Question

Quizplus · Accepted Answer

The exponential distribution has a parameter λ = 1/30 per second. The probability that more than 60 seconds elapse is given by P(X > 60) = e^(-λ*60) = e^(-60/30) = e^(-2) ≈ 0.135.

The Average Time Between Phone Calls Arriving at a Call