Aggregate Planning Practice Problem Armstrong Manufacturing Co. is preparing an aggregate production plan for next year. Its production manager, Leon Washington, has compiled the following information: Forecast of quarterly demand in hours per quarter: 250,000; 300,000; 400,000; 300,000 Beginning inventory in hours: 20,000 Initial employment level: 500 workers Hours worked per quarter by each worker: 400 hours of regular time, 100 hours of overtime (maximum) Inventory holding costs in dollars per hour per quarter: $4 Cost of regular time production per hour: $12 Cost of overtime production per hour: $15 Cost to hire a worker: $1000 Cost to Layoff a worker: $1500 Formulate an LP model to identify an optimal production plan by building a decision model in EXCEL.