A grocery store estimates that customers arrive at the rate of 15 per hour. The cashier can serve customers at a rate 20 per hour. Calculate the average number of customers in a line. Group of answer choices

The average number of customers in a line = 2.25

Step-by-step explanation:

We are given;

Mean arrival rate;a = 15 customers per hour

Mean service rate;s = 20 customers per hour

Now, we want to find the average number of customers in the line. It is given by the formula;

N_q = a(W_q) = a²/(s(s - a)

Plugging in relevant values, we have;

N_q = 15²/(20(20 - 15))

N_q = 225/100

N_q = 2.25

Step-by-step explanation: