"总利润增长12%，就意味着总收入会增长12%", logic

来源: 于 2008-10-13 23:11:55 [旧帖] [给我悄悄话] 本文已被阅读：次

error? simple example: rev = 100, fixed cost = 50, variable cost = 20%, then profit = 30, rev increase 12%: 100*(1+12%) = 112, fixed cost = 50, variable cost = 112 * 20% = 22.4, profit = 112 - 50 - 22.4 = 39.6. profit increase = (39.6 - 30)/30 = 32%. So profit increases at 32%, not 12%.

Also you are mixing indexing investment and 401k together, they are totally different.