PLEASE HELP ME$=$SHOW EXCEL FORMULAS. THANK YOU! $x=28$

Bob Stahl, the distribution manager at Forbes Industries, is considering using error addback for his DRP system. To evaluate its use, he compiled data for three periods on a sample product, the Scarlet Tiara. The initial DRP record is given here: $($Chapter $14)$

$\backslash$table$[[,,$Week$],[,,1,2,3,4,5],[$Forecast Requirements,,$40,40,40,40,40],[$In Transit,,$80,,,,],[$Projected Available Balance,$10,50,10,50,10,50],[$Planned Shipments,,,$80,,80,]]$

$Q=80,LT=1,ss=10$

a$.$ Develop the DRP records above for periods two through four given demands of $3+x,5+x,$ and $2+x$ in periods one, two, and three.

b$.$ Complete the same records using the error addback method. What differences occur?