设内含报酬率为I则内插法计算(16%-i)/(18%-16%)=(6.12-0)/(-3.17-6.12)I=17.32%
(18%-irr)(18%-16%7)=(-3.17-0)/(-3.17-6.12) IRR=18%-3.17/9.29*0.02=17.32%
