QUME 507 M4A exercises 12-2 What is the most important difference between PERT y CPM? 13-1 What is the problem of the waiting line? What are the components of a waiting line system? 13-4 Why must the service rate be greater than the arrival rate in a single-channel queuing system? 13-8 Give an example of a situation where the cost of waiting time is based on the time spent waiting in line. Give an example of a situation where the cost of waiting time is based on the waiting time in the system. 13-17 Cars arrive at the service window at a post office at a rate of 4 every 10 minutes. The average service time is 2 minutes. The Poisson distribution is suitable for the rate of arrivals and service times are distributed exponential way. a) What is the average time a car spends in the system? b) What is the average number of cars in the system? c) What is the average time that cars spend waiting to receive service? d) What is the average number of cars that are in the line behind the customer who is receiving the service? e) What is the probability that there are no cars in the window? f) What is the percentage of time that the employee Postal is busy? g) What is the probability that there are exactly two cars in the system