b$.$ Compare the costs to a level plan that uses inventory to absorb fluctuations, Inventory carrying cost is $$4$ per engine per month. Backlog cost is $$144$ per engine per month. There should not be a backlog in the last month. Set regular production equal to the monthly average of total forecasted demand. Assume that using overtime is not an option. $($Negative amounts should be indicated by a minus sign. Leave no cells blank $-$ be certain to enter $"$O$"$ wherever required. Round average inventory row, Inventory cost row, and Total row values to $1$ decimal.$)$

Period

Forecast

Output

$130$

$133$

$132$

$4$

$5$

$128$

$133$

$6$

$7$

$125$

$140$

$8$

$135$

Total

$1,056$

Regular

Output $-$ Forecast

Inventory

Beginning

Ending

Average

Backlog

Costs

Output

Regular

Inventory

Backorder

Total

$1$

$2$

$3$

$+$

b$.$ Compare the costs to a level plan that uses inventory to absorb fluctuations. Inventory carrying cost is $$4$ per engine per month. Backlog cost is $$144$ per engine per month. There should not be a backlog in the last month. Set regular production equal to the monthly average of total forecasted demand. Assume that using overtime is not an option. $($Negative amounts should be indicated by a minus sign. Leave no cells blank $-$ be certain to enter $"0"$ wherever required. Round average inventory row, Inventory cost row, and Total row values to $1$ decimal.$)$