The following table contains information concerning four jobs that are awaiting processing at a work center.

$\backslash$table$[[$Job Time,,$],[$Job$,($days$),$Due Date $($days$)],[$A$,14,20],[$B$,10,16],[$C$,7,15],[$D$,6,17]]$

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a$.$ Sequence the jobs using

$(1)$ FCFS$,$

$(2)$ SPT$.$

$(3)$ EDD, and

$(4)$ CR$.$ Assume the list is by order of arrival.

$\backslash$table$[[$Sequence for First come, first served,$],[$Sequence for Shortest processing time,$],[$Sequence for Earliest due date,$],[$Sequence for Critical ratio,$]]$

b$.$ For each of the methods in part a$,$ determine

$(1)$ the average job flow time,

$(2)$ the average tardiness, and

$(3)$ the average number of jobs at the work center.

Note: Round your intermediate calculations and final answers to $2$ decimal places.

$\backslash$table$[[,\backslash$table$[[$First Come,$],[$First Served$]],\backslash$table$[[$Shortest$],[$Processing$],[$Time$]],\backslash$table$[[$Earliest Due$],[$Date$]],$Critical Ratio$],[$Average job flow time,,,,$],[$Average tardiness,,,,$],[$Average number of jobs,,,,$]]$

c$.$ Which method is superior to the others?

First come, first served

Shortest processing time

Earliest due date

Critical ratio

None are superior