##### 2020/6/1 星期一 10:59:38

eac = ac + etc 怎么会变成 bac/cpi

信管网 2020/6/1 星期一 11:01:38

eac = etc+ac

=(bac-ev)/cpi +ac

=bac/cpi—ev/cpi +ac

然后cpi = ev/ac , 带入刚刚公式中

eac = bac/cpi—ev/cpi +ac

= bac/cpi—ev/(ev/ac）+ac =bac/cpi—ac +ac =bac/cpi

信管网 2020/6/1 星期一 11:02:04

非典型偏差：etc = bac-ev

典型偏差：etc = (bac-ev)/cpi

非典型偏差：eac = bac + ac–ev= bac- cv

典型偏差：eac = bac / cpi= etc + ac