Answer:
-3
Step-by-step explanation:


Negative 72.75 is your product. It is very simple once you understand it.
Answer:
18 minutes
Step-by-step explanation:
Given that:
The arrival time = 3 customers / hour
The avg. service rate (s) = 12 minutes per customer
To hour, we have:

s = 5 customers/ hour
Thus, the required average time for a customer needs to wait in line is:

To minutes;

= 18 minutes