Answer:
On average how many requests are in the first department (including those who are waiting) is 1.32.
Step-by-step explanation:
In this case, use the Little's law of queuing theory.
The Little's law states that the average number of customers in a fixed system (L) is equal to the average effective arrival rate (λ) multiplied by the average time a customer spends in the system (W).
The number of requests per hour in the 1st department is, λ₁ = 4.
It is provided that 20% are rejected directly by the 1st department without going into the 2nd department.
Then the number of requests per hour is, λ₂ =
The average time a customer spends in the 1st department,
W₁ = 20 minutes = 0.33 hours.
The average time a customer spends in the 1st department,
W₂ = 60 minutes = 1 hour
On average how many requests are in the first department (including those who are waiting) is:
<em>L</em> = λ₁ × W₁
= 4 × 0.33
= 1.32
Thus, on average how many requests are in the first department (including those who are waiting) is 1.32.