设内含报酬率为I 100*(P/F I 5)+100*4%*(P/A I 5)=95 假定利率为6% 100*(P/F 6% 5)+100*4%*(P/A 6% 5)=100*0.7473+4*4.2124=91.58 假定利率为3% 100*(P/F 3% 5)+100*4%*(P/A 3% 5)=100*0.8626+4*4.5797=104.58 (95-91.58)/(I-6%)=(104.58-91.58)/(3%-6%) I=5.2%