p.p1%2525252520%252525257Bmargin%252525253A%25252525200.0px%25252525200.0px%25252525200.0px%25252525200.0px%252525253B%2525252520font%252525253A%252525252012.0px%2525252520%2525252526%252525252339%252525253B.PingFang%2525252520SC%2525252526%252525252339%252525253B%252525257D%252525250Aspan.s1%2525252520%252525257Bfont%252525253A%252525252012.0px%2525252520%2525252526%252525252339%252525253BHelvetica%2525252520Neue%2525252526%252525252339%252525253B%252525257D 某公司每年以每个单位 30 美元的价格采购 6000 个单位的某种产品,每采购一次的采购 125 美元,年保管费率为 20% ,求经济订货批量、库存总成本(购入成本 + 订货成本 + 保管成本)