请教这道题用计算器计算IRR

NO.PZ2017092702000029问题如下A funreceives investments the beginning of eayeangenerates returns shown in the table. Whireturn measure over the three-yeperiois negative?A.Geometric mereturn B.Time-weighterate of return C.Money-weighterate of returnC is correct. The money-weighterate of return consirs both the timing anamounts of investments into the fun The investment the beginning of Ye1 will worth $1,000(1.15)(1.14)(0.96) = $1,258.56 the enof Ye3. The investment ma the beginning of Ye2 will worth $4,377.60 = $4,000(1.14)(0.96) the enof Ye3. The investment of $45,000 the beginning of Ye3 creases to a value of $45,000 (0.96) = $43,200 the enof Ye3. Solving for r,1,000+4,0001+r+45,000(1+r)2=1,258+4,337.60+43,200(1+r)31,000+\frac{4,000}{1+r}+\frac{45,000}{{(1+r)}^2}=\frac{1,258+4,337.60+43,200}{{(1+r)}^3}1,000+1+r4,000​+(1+r)245,000​=(1+r)31,258+4,337.60+43,200​results in r = –2.08%Note thB is incorrebecause the time-weighterate of return (TWR) of the funis the same the geometric mereturn of the funanis thus positive: TWR = √ 3 (1.15) (1.14) (0.96) - 1 = 7.97%跟答案完全不一样？可以告知我这算的是啥吗。。。蒙的

NO.PZ2017092702000029 问题如下 A funreceives investments the beginning of eayeangenerates returns shown in the table. Whireturn measure over the three-yeperiois negative? A.Geometric mereturn B.Time-weighterate of return C.Money-weighterate of return C is correct. The money-weighterate of return consirs both the timing anamounts of investments into the fun The investment the beginning of Ye1 will worth $1,000(1.15)(1.14)(0.96) = $1,258.56 the enof Ye3. The investment ma the beginning of Ye2 will worth $4,377.60 = $4,000(1.14)(0.96) the enof Ye3. The investment of $45,000 the beginning of Ye3 creases to a value of $45,000 (0.96) = $43,200 the enof Ye3. Solving for r,1,000+4,0001+r+45,000(1+r)2=1,258+4,337.60+43,200(1+r)31,000+\frac{4,000}{1+r}+\frac{45,000}{{(1+r)}^2}=\frac{1,258+4,337.60+43,200}{{(1+r)}^3}1,000+1+r4,000​+(1+r)245,000​=(1+r)31,258+4,337.60+43,200​results in r = –2.08%Note thB is incorrebecause the time-weighterate of return (TWR) of the funis the same the geometric mereturn of the funanis thus positive: TWR = √ 3 (1.15) (1.14) (0.96) - 1 = 7.97% 计算器一直报error 5

NO.PZ2017092702000029 问题如下 A funreceives investments the beginning of eayeangenerates returns shown in the table. Whireturn measure over the three-yeperiois negative? A.Geometric mereturn B.Time-weighterate of return C.Money-weighterate of return C is correct. The money-weighterate of return consirs both the timing anamounts of investments into the fun The investment the beginning of Ye1 will worth $1,000(1.15)(1.14)(0.96) = $1,258.56 the enof Ye3. The investment ma the beginning of Ye2 will worth $4,377.60 = $4,000(1.14)(0.96) the enof Ye3. The investment of $45,000 the beginning of Ye3 creases to a value of $45,000 (0.96) = $43,200 the enof Ye3. Solving for r,1,000+4,0001+r+45,000(1+r)2=1,258+4,337.60+43,200(1+r)31,000+\frac{4,000}{1+r}+\frac{45,000}{{(1+r)}^2}=\frac{1,258+4,337.60+43,200}{{(1+r)}^3}1,000+1+r4,000​+(1+r)245,000​=(1+r)31,258+4,337.60+43,200​results in r = –2.08%Note thB is incorrebecause the time-weighterate of return (TWR) of the funis the same the geometric mereturn of the funanis thus positive: TWR = √ 3 (1.15) (1.14) (0.96) - 1 = 7.97% 为什么最后的CF3不是45000*-4%。最后的CF3不知道原因，没有看懂是怎么求出来的

NO.PZ2017092702000029 问题如下 A funreceives investments the beginning of eayeangenerates returns shown in the table. Whireturn measure over the three-yeperiois negative? A.Geometric mereturn B.Time-weighterate of return C.Money-weighterate of return C is correct. The money-weighterate of return consirs both the timing anamounts of investments into the fun The investment the beginning of Ye1 will worth $1,000(1.15)(1.14)(0.96) = $1,258.56 the enof Ye3. The investment ma the beginning of Ye2 will worth $4,377.60 = $4,000(1.14)(0.96) the enof Ye3. The investment of $45,000 the beginning of Ye3 creases to a value of $45,000 (0.96) = $43,200 the enof Ye3. Solving for r,1,000+4,0001+r+45,000(1+r)2=1,258+4,337.60+43,200(1+r)31,000+\frac{4,000}{1+r}+\frac{45,000}{{(1+r)}^2}=\frac{1,258+4,337.60+43,200}{{(1+r)}^3}1,000+1+r4,000​+(1+r)245,000​=(1+r)31,258+4,337.60+43,200​results in r = –2.08%Note thB is incorrebecause the time-weighterate of return (TWR) of the funis the same the geometric mereturn of the funanis thus positive: TWR = √ 3 (1.15) (1.14) (0.96) - 1 = 7.97% 为什么客户的收益是在最后一年的cashflow里，而不是在对应的cf1、cf2、cf3？