A single-server queueing system with FIFO service discipline was simulated for 40 minutes. Customers can arrive in groups. Let X(t) be the number of entities in the system at time t. A single replication produced the following sample path, with X(40) = 0 (the system emptied out). interval [0,4) [4, 10) X(t) 1 3 The plot of X(t), 0 t 40 will help towards answering the following questions. (a) Compute the average number of entities in the system during the simulated time window. [10,21) [21,25) [25, 30) [30,36) [36,40) 4 3 1 0 1 (b) Compute the average time-in-system for the entities during the simulated time window. (c) [Bonus question: 1 point] Compute the average number of entities waiting in line prior to service during this time window.