Use the following info to answer questions $2-4$

grocery store has two checkout counters. Each counter can serve $5$ customers per hour on average. It is estimated that a customer completes the purchase and needs to check out every $15$ min on average. Assume that the inter$-$arrival time and the service time folows exponential distribution

What is$.$the.average.arrival rate.of the whole system?

$15$ min$/$customer

$4$ customers$/$hr

$8$ customers$/$hr

$7\mathrm{.}5$ min$/$customer

Question $3$

What is the average service rate of the whole system?

$10$ customers$/$hr

$12$ min$/$customer

$5$ customers$/$hr

$6$ min$/$customer

Question $4$

Constrained.by$.$the.layout.of the grocery store the manager requires customers to form two separate lines with each one dedicated to a checkout counter. This means. that a$.$customer.in$.$one.line can only be served by the counter for that line. To reduce customers' average waiting time. the manager should do which of the following?

$-$ Empty the checkout area of all shelves to expand the waiting space

$-$ Clean up the checkout area so newly$-$arriving customers can see which line is shorter

$-$ Add TV screens in the checkout area to display brand commercials

$-$ Allocate space in the checkout area for items that customers can quickly buy before joining a line, e$.$g$.$ snacks and cellphone cases