A local semiconductor firm, Superchip, is planning its workforce and production levels over the next year. The firm makes a variety of microprocessors and uses sales dollars as its aggregate production measure. Based on the orders received and sales forecasts provided by the marketing department, the estimate of dollar sales for the next year by month is as follows:

Month	Production Days	Predicted Demand (in 10,000)
Jan	22	340
Feb	16	380
Mar	21	220
Apr	19	100
May	23	490
June	20	625
July	24	375
Aug	12	310
Sep	19	175
Oct	22	145
Nov	20	120
Dec	16	165

Inventory holding costs are based on a 25 percent annual interest charge. It Is anticipated that there will be 675 workers on the payroll at the end of the current year and inventories will amount to $120,000. The firm would like to have at least $100,000 of inventory at the end of December next year. It is estimated that each worker accounts for an average of $60,000 of production per year (assume that one year consists of 250 working days). The cost of hiring a new worker is $200, and the cost of laying off a worker is $400.

Find the minimum workforce plan and the total cost of this plan.

Solve it using MANUAL table and calculations. NOT EXCEL OR LINEAR PROGRAMMING.