#questionGo-Fast Travel agency has a phone reservation system with 5 lines answered by one travel agent. that means 4 customers can be placed on hold while one is being served. if all 5 lines are in use, a new caller will get a busy signal. potential customers call the agency on average every 15 minutes (exponential distribution). an average phone call lasts 12 minutes (exponential distribution). On average per hour, how many customers cannot get through to the travel agent? on average, how long must a customer wait before his/her call is answered?..