作业求助

linchan

Eight months ago, Louise agreed to pay Thelma $750 and $950, six and twelve
  B" e' T' j$ `0 j4 \+ z/ kmonths respectively from the date of the agreement. With each payment, Louise
4 p% R' c& v' c/ N6 e  eagreed to pay interest at the rate of 9.5% pa from the date of the agreement. Louise
$ t) q& N, \$ e! w* Lfailed to make the first payment and now wishes to settle her obligations with a
single payment four months from now. What payment should Thelma be willing to
accept if money can earn 7.75%? （最好有过程）

littledognancy

Suppose Intr is annually compounded                                       
" @0 ?- x# [7 j3 ]* s* L                Month 0        Mon. 8                  Mon. 12
# J* d9 W+ n/ K& y. }% |( H+ GCash Principal        X        -750                  -950       
7 F( r7 Y7 @' G4 ECash Intr (Should Pay)                -X*9.5%*8/12          -(X-750)*9.5%*4/12               
/ R  O6 V& l4 [  d# ]PV at mon 0        X        -[750+X*9.5%*8/12]          -[950+(X-750)*9.5%*4/12]
                                                 /(1+7.75%*8/12)           /(1+7.75%*12/12)
3 M+ R0 i3 X! `
these 3 should add up to 0, i.e. NPV at month 0 is 0.
                                       
3 J! ?' G  L- v8 `! uConclusion        X        =        1729.8               
                                       
So, Initial borrowing was        1730        *(1+7.5%)        1859.5        approx.         $1,860
# e6 M* y  L$ c1 z2 R

littledognancy

Finance 学得不好所以不知道做得对不对。。。看着办吧~ 也许有用。

linchan

对了，答案是$1856.32