Scheduling Algorithms

**Step 1: Determine the process execution order based on priority.**
We execute the processes in order of priority (highest to lowest):

- **P2** (Priority 1) runs first.

- **P4** (Priority 2) runs next.

- **P1** (Priority 3) runs after P4.

- **P3** (Priority 4) runs after P1.

- **P5** (Priority 5) runs last.

**Step 2: Calculate the waiting time.** The waiting time for each process is the total time the process spends waiting in the ready queue before it starts execution.

- **P2**: Waits 0 ms (it is the first to execute).

- **P4**: Waits for P2 to finish, which is 1 ms.

- **P1**: Waits for P2 and P4 to finish, which is 1 + 1 = 2 ms.

- **P3**: Waits for P2, P4, and P1 to finish, which is 1 + 1 + 10 = 12 ms.

- **P5**: Waits for P2, P4, P1, and P3 to finish, which is 1 + 1 + 10 + 4 = 16 ms.

**Step 3: Calculate the average waiting time.** The average waiting time is the sum of the waiting times divided by the number of processes:

Thus, the correct answer is **5.2 milliseconds**.