Five batch jobs. $A$ through $E$, arrive at a computer center at almost the same time. They have estimated running times of $10, 6, 2, 4,$ and $8$ minutes. Their (externally determined) priorities are $3, 5, 2, 1,$ and $4,$ respectively, with $5$ being the highest priority. For each of the following scheduling algorithms, determine the mean process turnaround time. Ignore process switching overhead.
- Round robin.
- Priority scheduling.
- First-come, first-served $($run in order $10, 6, 2, 4, 8)$.
- Shortest job first.
For $(a)$, assume that the system is multiprogrammed, and that each job gets its fair share of the CPU. For $(b)$ through $(d),$ assume that only one job at a time runs, until it finishes. All jobs are completely CPU bound.
