作业求助

linchan

Eight months ago, Louise agreed to pay Thelma $750 and $950, six and twelve
months respectively from the date of the agreement. With each payment, Louise
agreed to pay interest at the rate of 9.5% pa from the date of the agreement. Louise
9 L: H& @5 j5 @1 K  ]failed 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                                       
+ r. ]' z# p5 Q7 T                Month 0        Mon. 8                  Mon. 12
# L% k3 I) D. L. Y5 hCash Principal        X        -750                  -950       
8 }1 M/ q" S8 vCash 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]
                                                 /(1+7.75%*8/12)           /(1+7.75%*12/12)

these 3 should add up to 0, i.e. NPV at month 0 is 0.
; g" k2 Y# S0 J1 @: z4 H2 L                                       
# ^1 c5 [4 o# y* q; A8 kConclusion        X        =        1729.8               
# S9 ]. w" p' H+ u7 m                                       
So, Initial borrowing was        1730        *(1+7.5%)        1859.5        approx.         $1,860
& \/ V" N8 t# h0 R! h% w+ V

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