作业求助

linchan

Eight months ago, Louise agreed to pay Thelma $750 and $950, six and twelve
  {% b. f2 Z' I4 @months respectively from the date of the agreement. With each payment, Louise
3 k( z( f& A3 @7 M3 `agreed to pay interest at the rate of 9.5% pa from the date of the agreement. Louise
; w! A% v; M8 B: b5 Q1 p% gfailed 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                                       
                Month 0        Mon. 8                  Mon. 12
" J+ _; Z* R/ L8 P. c$ }- iCash Principal        X        -750                  -950       
Cash Intr (Should Pay)                -X*9.5%*8/12          -(X-750)*9.5%*4/12               
+ [6 ~, ~  U$ v1 o+ m, Y7 R9 j( `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)
. ?% H/ E$ V+ e* F& J
& @+ E# ^$ M) h' E& q5 c( ?these 3 should add up to 0, i.e. NPV at month 0 is 0.
4 D6 e; V! k. d6 U0 X                                       
" ~  H  \6 C' m8 QConclusion        X        =        1729.8               
                                       
6 t. ^& X5 H) r  M6 d' TSo, Initial borrowing was        1730        *(1+7.5%)        1859.5        approx.         $1,860

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