Design a spreadsheet that can be used to evaluate aggregate plans. The spreadsheet should enable the evaluation of:

1. pure strategy based on leveling production,
2. pure strategy based on minimizing inventory by laying off/hiring as needed,
3. a mix of the above two.

The spreadsheet should have the following headings:

1	2	3	4	5	6	7	8	9	10	11
		Sales in		Production
Month	Sales	labor-hour	Working	labor-hour	Number of	Workers	Workers	Beginning	Ending	Backorder
	(Million)	(000s)	days	(000s)	Workers	Hired	Fired	Inventory	Inventory

All but columns 1, 2, and 4 should be computed using cell formulas. Column 5 should allow for using cell formulas in the case of level production or direct input for mixed plans. The cost of any plan, in total and for each cost component, should be computed without additional effort. Assume an 8-month horizon and use the following data to test your spreadsheet:

Sales per direct labor hour	$30
Hiring cost	$ 300.0
Firing cost	$ 500.0
Regular labor cost per hour	$ 15.00
Overtime premium cost per hour	$ 7.50
Backorder cost per month	2%
Inventory carrying cost per month	1%
Beginning inventory	$ 400000
Desired ending inventory in September	$ 0
Number of Employees as of end of December	1900

Month	Sales	Working
	(Million)	days
January	8.0	20
February	7.4	21
March	11.2	23
April	11.0	20
May	9.8	22
June	8.0	22
July	8.0	10
August	10.6	23
September	9.4	20

I'm getting stuck trying to find the ending inventory and total cost. Once I put it in the solver, it messes up my spreadsheet