股票买入价格=45000/5000=9(元),设内部收益率为R,则有:0.35/(1+R)+0.32/(1+R)2+0.55/(1+R)3+12/(1+R)3=9, 即0.35/(1+R)+0.32/(1+R)2+0.55/(1+R)3+12/(1+R)3-9=0； 当R=14%时,0.35/(1+14%)+0.32/(1+14%)2+0.55/(1+14%)3+12/(1+14%)3-9=0.02； 当R=16%时,0.35/(1+16%)+0.32/(1+16%)2+0.55/(1+16%)3+12/(1+16%)3-9=-0.42； (R-14%)/(16%-14%)=(0-0.02)/(-0.42-0.02), R=(0-0.02)/(-0.42-0.02)×(16%-14%)+14%=14.09%｡