Process A with burst time of $5$ milliseconds and priority $3.$

$-$ Process B with burst time of $8$ milliseconds and priority $2.$

$-$ Process C with burst time of $4$ milliseconds and priority $1.$

$-$Process D with burst time of $6$ milliseconds and priority $1.$

Shortest Job First $($SJF$)$: Apply Shortest Job First Scheduling to

execute the processes. Draw the Gantt chart and calculate Average

waiting time.