It could be argued that all costs are variable to some degree. It is generally beneficial for companies to reduce the costs of manufacturing their products to ensure profitability. Therefore, many managers monitor profitability by dividing the variable costs by the total revenue to determine the costs as a percentage of the sales. For example, a foodservice company might spend about $500 on plastic wrap to pack 2,000 sandwiches. A product profitability analysis might determine that production costs could be lowered if they bought plastic wrap in bulk...