In: Statistics and Probability
The photo booth at the Apple County fair takes snapshots in exactly 90 seconds. Customers arrive at the machine according to a Poisson distribution at the mean rate of 25 per hour. Using this information, determine the following:
a. | the average number of customers waiting to use the photo machine |
b. | the average time a customer spends in the system |
c. | the probability an arriving customer must wait for service. |
Answer:
Given,
Arrival rate
= 25 per hour
Service rate
= 3600/90 = 40 per hour
a)
Average number of customers waiting to use the photo machine Lq
=
^2/
(
-
)
substitute values
= 25^2 / (40(40 - 25))
= 1.042
b)
average time a customer spends in the system W = 1/(-
)
= 1 /(40-25)
= 1/15
= 0.0667 *60
= 4 min
c)
probability an arriving customer must wait for service =
/
= 25/40
= 0.625
= 62.5%