计算结果跟答案对不上

A project has the following annual cash flows

Year 0:-4662005

Year 1:22610723

Year 2:-41 072 261

Year 3:33 116 550

Year 4 : 10 000 000

which of following discount rate most likely produces the highest net present value

A:8% B 10% C 15%

下面是我的计算过程，请指点。

CF 清零

CF0=-4662005

C01=22610723

C02=-41 072 261

C03=33 116 550

C04=10 000 000

I= 8

CPT NPV=14700289.47

I=10

NPV=13660269

I=15

NPV=11435164.85

可是答案是 15%

那个sample数据有问题，第四年的数据应该是-10000000