Lou operates a cab service specifically tailored to provide safe and comfortable transportation for seniors in his town. He owns five cabs, each staffed by a dedicated driver. Upon receiving a service call, Lou promptly dispatches one of these drivers to pick up the customer. The operational details are as follows: • Each driver takes an average of 15 minutes to arrive at the customer's location after being dispatched. • The journey from the customer's pickup location to their destination averages 25 minutes. • Lou’s service receives an average of 2.5 calls per hour. For analytical purposes, you can assume that both the arrival of service calls (demand) and the service times have coefficients of variation (CV) equal to 1. (a) What is the average waiting time for a customer from the moment they place a service call to Lou until a cab arrives to pick them up? (For answering this question carefully think about different stages of processes, and what a customer is doing in each stage. It will be helpful to draw a process flow diagram).