Can someone please twll me why my solver us wrong? and then answer the following questions.

he production manager for the Classic Boat Corporation must determine how many units of the

Classic $21$ model to produce over the next four quarters. The company has a beginning inventory of

$100$ Classic $21$ boats, and demand for the four quarters is $2000$ units in quarter $1,4000$ units in

quarter $2,3000$ units in quarter $3,$ and $1500$ units in quarter $4.$ The firm has limited production capacity

in each quarter. That is$,$ up to $4000$ units can be produced in quarter $1,3000$ units in quarter $2,2000$

units in quarter $3,$ and $4000$ units in quarter $4.$ Each boat held in inventory in quarters $1$ and $2$ incurs

an inventory holding cost of $$250$ per unit; the holding cost for quarters $3$ and $4$ is $$300$ per unit. The

production costs for the first quarter are $$10,000$ per unit; these costs are expected to increase by

$10\%$ each quarter because of increases in labor and material costs. Management specified that the

ending inventory for quarter $4$ must be at least $500$ boats.

$($a$)$ Formulate a linear programming model that can be used to determine the production

schedule that will minimize the total cost of meeting demand in each quarter subject to the

production capacities in each quarter and also to the required ending inventory in quarter $4.$

$($b$)$ Use Excel to solve the linear program formulated in part $($a$).$ Clearly state the production

plan: for each quarter, how many units to manufacture, the ending inventory, and the costs

incurred. You can use a table to summarize this information.

$($c$)$ Interpret each of the shadow prices corresponding to the constraints developed to meet

demand in each quarter. Based on these shadow prices, what advice would you give the

production manager?

$($d$)$ Interpret each of the shadow prices corresponding to the production capacity in each

quarter. Based on each of these shadow prices, what advice would you give the production

manager?