内插法是一种计算方法,给您举例教材第二章72页图2-3(Excel表格)计算内含报酬率 使用的内插法
1、 内含报酬率
20000=560000*(P/F,IRR,1)+696028*(P/F,IRR,2)+1350773*(P/F,IRR,3)+392874*(P/F,IRR,4)
当IRR=16%时,
等式右边=560000*(P/F,16%,1)+696028*(P/F,16%,2)+1350773*(P/F,16%,3)+392874*(P/F,16%,4)=560000*0.8621+696028*0.7432+1350773*0.6407+392874*0.5523=2082488.58;
结果大于20000
当IRR=18%时,
等式右边=560000*(P/F,18%,1)+696028*(P/F,18%,2)+1350773*(P/F,18%,3)+392874*(P/F,18%,4)=560000*0.8475+696028*0.7182+1350773*0.6086+392874*0.5158=1999212.17;
结果小于20000.
运用内插法列式:
(18%-16%)/(IRR-16%)=(1999212.17-2082488.58)=(20000-2082488.58)
然后解一元一次方程,得出的IRR就是内含报酬率
IRR=16%+[82488/(82488+789)]*(18%-16%)
=16%+1.89%=17.98%
2、教材65页也有介绍内插法的,最下面那个插值法就是内插法。
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