Vacation Inns, a chain of hotels operating in the southeastern region of the U.S., uses a toll-free telephone number to take reservations for all of its hotels. An average of 12 calls are received per hour. The probability distribution that describes the arrivals is unknown.
Over a period of time, it is determined that the average caller spends 6 minutes on hold waiting for service. Find the average number of callers in the queue by using Little's Law.