Crestline Bank would like to minimize its labor costs by hiring as few tellers as possible while still maintaining a stated service level. In particular, it desires the average waiting time for a customer from the time he or she enters a line until the transaction is completed to be at most three minutes. Define: T = the number of tellers employed by Crestline Bank W(T) = a function giving the average customer waiting time when there are T tellers Write a mathematical model for this problem. Is it an optimization or a prediction model?