The J. Page Furniture Company has the following information available regarding costs at various levels of monthly production: Production volume (units) 16,000 Units 22,000 Units Direct materials $ 70,000 $96,250 Direct labor 66,000 90,750 Indirect materials 21,000 28,875 Supervisors' salaries 12,000 12,000 Depreciation on plant and equipment 10,000 10,000 Maintenance 32,000 48,000 Utilities 15,000 21,000 Insurance on plant and equipment 1,600 1,600 Property taxes on plant and equipment 2,000 2,000 Total $229,600 $310,600 Identify each of the costs above as being variable, fixed, or mixed