作业求助

linchan

Eight months ago, Louise agreed to pay Thelma $750 and $950, six and twelve
' k/ S/ X! g/ e4 J1 h+ P+ H8 J% O! ~months respectively from the date of the agreement. With each payment, Louise
0 {2 x' m, L3 A! ]+ xagreed to pay interest at the rate of 9.5% pa from the date of the agreement. Louise
failed to make the first payment and now wishes to settle her obligations with a
* |" b- K8 e0 n$ |( u( K- K: fsingle 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                                       
, P9 [1 ?( L. ~, g1 F& }) w5 i                Month 0        Mon. 8                  Mon. 12
; y: c, d) e" _# jCash Principal        X        -750                  -950       
( [7 d+ Y0 _$ A6 x; _Cash Intr (Should Pay)                -X*9.5%*8/12          -(X-750)*9.5%*4/12               
PV at mon 0        X        -[750+X*9.5%*8/12]          -[950+(X-750)*9.5%*4/12]
! k8 N& t/ O) n$ r& d8 h" j, A                                                 /(1+7.75%*8/12)           /(1+7.75%*12/12)
% h2 n, _- u8 E" V0 R3 Z
these 3 should add up to 0, i.e. NPV at month 0 is 0.
; B  W. e( f2 Q; H                                       
4 Z; E. y8 W4 t2 Y  Q& Y6 rConclusion        X        =        1729.8               
2 \6 k  T4 x0 R6 t% h8 A4 p' W                                       
So, Initial borrowing was        1730        *(1+7.5%)        1859.5        approx.         $1,860
5 N. D* `, Q3 v+ I% Y- S% M

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