A cafe is ruing 8 hours a day with the expected capability to serve 120 customers each day. Suppose during each day's 8 hour operating time, 96 customers arrive on average and there is a single line formed outside of the cafe. Suppose the manager wants to improve profitability by having no more than a 30% chance that no more than 3 customers will be in the system at any time, what should be the service rate that can reach this goal?