If an average of 12 customers is served per hour, what is the probability that the next customer will arrive in 3 minutes or more?
A) 0.55
B) 0.30
C) 0.45
D) 0.39

Question

Quizplus · Accepted Answer

The average rate is 12 customers per hour, which is 1 customer every 5 minutes. The probability that the next customer arrives in 3 minutes or more is the complement of the probability that the customer arrives in less than 3 minutes. Using the exponential distribution, P(X ≥ 3) = 1 - P(X < 3) = 1 - (1 - e^(-3/5)) = e^(-3/5) ≈ 0.45.

If an Average of 12 Customers Is Served Per Hour