Consider the following set of processes, with the length of the CPU execution time given

in milliseconds. The processes are assumed to have arrived in the order P1, P2, P3, P4, at

the following times.

Process Arrival Time Execution Time

---------------------------------------------------------------------------------

P1 0 6

P2 1 3

P3 3 4

P4 4 1

(a) Draw CPU grant chart that illustrates the execution of these processes using the FcFS,

SJF with non-preemptive, and SJF with preemptive scheduling, respectively.

(b) Calculate the average waiting time over all processes for FcFS, SJF with non-

preemptive, and SJF with preemptive.