Consider the following table of arrival time and burst time for three process P
o P
1 and P
2| Process | Arrival Time | Burst Time |
| Po | 0 ms | 9 ms |
| P1 | 1 ms | 4 ms |
| P2 | 2 ms | 9 ms |
The preemptive shortest job first scheduling algorithm is used. Scheduling is carried out only at arrival or completion of process. What is the average waiting time for the three process