A fast food restaurant has recently installed a drive-in window to serve its customers. The average service time has been estimated to be 4 minutes and follows an exponential distribution. The average inter-arrival time of the cars at the drive-in window is 5 minutes and follows an exponential distribution. 1) What is the expected number of customers who will arrive at the drive-in window during the next 20 minutes? 2) What is the standard deviation of the arrival rate in the next 20 minutes? 3) Produce the main Performance Measures for this queuing system.