The time between arrivals at an ATM machine follows an exponential distribution with $\theta = 10$ minutes. Find the probability that between 15 and 25 minutes will pass between arrivals.
A) 0.141045
B) 0.223130
C) 0.082085
D) 0.305215

Question

Quizplus · Accepted Answer

The probability that between 15 and 25 minutes will pass between arrivals is given by:$$P(15 < X < 25) = P(X < 25) - P(X < 15)$$$$= 1 - e^{-25/10} - (1 - e^{-15/10})$$$$= 0.141045$$

The Time Between Arrivals at an ATM Machine Follows an Exponential