以往我们往往认为,只要售价和成本挖制情况不变,产销量变动时单位成本和单位产品的利润也保持不变;因此,销售利润总额将随产销量的变动而作正比例变动。企业常常是这样预测销售利润,并这样考核销售利润计划完成情况的,国家机关也常常是这样 In the past, we often considered that as long as the price and the cost of excavation remain unchanged, the unit cost and the profit of the unit product will remain unchanged when the production and sales volume changes; therefore, the total sales profit will change in proportion to the change in production and sales volume. Companies often predict sales profits in this way, and thus assess the completion of sales profit plans. This is often the case for state agencies.