please help with this IN EXCEL!!!!! show all steps and equations and solver and explain results!!!! thanks in advance will rate fast. A company faces the aggregate planning problem shown in the table below. Cost of regular production is $$8$ per unit, the cost of producing the same unit on overtime is $$15,$ the cost of subcontracting is $$12$ per unit, and the cost of carrying a unit in inventory from one month to the next is $$6.$

$\backslash$table$[[,$January,February,March,April,May$],[$Forecast$,400,800,1200,700,300],[\backslash$table$[[$Beginning$],[$Inventory$]],100,,,,],[$Regular Time,,,,,$],[$Overtime$,,,,,],[$Subcontracting$,,,,,],[$Ending Inventory,,,,,$]]$

The labour contract at the plant prohibits both overtime and subcontracting output to exceed $400$ units in any five$-$month window. The plant capacity is $20$ units per day produced using two shifts and the plant runs seven days a week. By policy, management wants to avoid stock$-$outs. What is the optimal total cost of the aggregate plan developed?