This question is incomplete, the complete question is;
A bank is designing a new branch office and needs to determine how much driveway space to allow for cars waiting for drive-up teller service.
The drive-up service will have three tellers and a single waiting line. At another branch of the bank in a similar setting, the average service time for drive-up tellers is four minutes per customer, and average arrival rate is 36 customers per hour. It is expected that the new bank will have similar characteristics.
How many spaces should be provided to have a 96 percent probability of accommodating all of the waiting cars?
Answer:
Eleven (11) spaces should be provided to have a 96 percent probability of accommodating all of the waiting cars
Explanation:
Given that:
the average service time for drive-up tellers is four (4) minutes per customer at each branch
Average number of customers per hour is 36
Therefore for 36 customers,
the branch can give ( 36 / 4 ) = 9, mins each customer
from the question, there is a probability of 96%
so we will calculate on the 9 as mentioned above
96% of 9 = 0.96
0.96 × 9= 8.64
If there are 3 tellers in a single line- , then
8.64 + 3 = 11.64 approximately 11
Therefore Eleven (11) spaces should be provided to have a 96 percent probability of accommodating all of the waiting cars