At the bus station, there are six lines for arriving passengers, each staffed by a single worker. The arrival rate for passengers is 108 per hour and each passenger takes (on average) 3.1 minutes for a worker to process. The coefficient of variation for arrival time is 1.5 and the coefficient of variation for service time is 1.1 . (Round your answer to three decimal places.) On average, how many customers will be waiting in the queue? passengers