please help answer these!!

2 Staffing at the Optimal Utilization A large-club grocery store is attempting to staff its check-out registers. Currently, the arrival rate is =135 customers per hour and each server has an average service time of ZT=400 seconds (note this is roughly double the time for a regular grocery store-the higher time is to account for large, bulk items). Our usual assumption holds where the interarrival and service times follow an exponential distribution. 6. Calculate the average service rate (in hours to match ). What is the distribution of the service time T ? 7. What is the marginal probability that a customer's service time will be greater than 540 seconds ( 0.15 hours), that is P(T>0.15) ? Calculate the bounded (joint) probability that a customer's service time will be between 360 seconds ( 0.1 hours) and 720 seconds ( 0.2 hours), that is P(0.10.15) ? Calculate the bounded (joint) probability that a customer's service time will be between 360 seconds ( 0.1 hours) and 720 seconds ( 0.2 hours), that is P(0.1