Compound interest practice Q: Scheduled payments of 1400duetodayand1400duetodayand160

[chabongden]

I have a question about compound interest, but i got the answer wrong and i don't really know what i did wrong, Can someone figure it out?
Scheduled payments of [FONT=MathJax_Main]1400[FONT=MathJax_Math-italic]d[FONT=MathJax_Math-italic]u[FONT=MathJax_Math-italic]e[FONT=MathJax_Math-italic]t[FONT=MathJax_Math-italic]o[FONT=MathJax_Math-italic]d[/FONT][FONT=MathJax_Math-italic]a[/FONT][FONT=MathJax_Math-italic]y[/FONT][FONT=MathJax_Math-italic]a[/FONT][FONT=MathJax_Math-italic]n[/FONT][FONT=MathJax_Math-italic]d[/FONT][/FONT][/FONT][/FONT][/FONT]1400duetodayand[/FONT]1600 due with interest at 11.5% compounded annually in five years are to be replaced by two equal payments. The first replacement payment is due in 18 months and the second payment is due in 4 years. Determine the size of the two replacement payments if interest is 11% compounded quarterly and the focal date is 18 months from now.[/FONT]
By using 2 formula: FV=PV(1+i)^n and PV=FV(1+i)^(-n)
I have:
1400(1+0.115)^1.5+ 1600(1+0.115)^3.5 = X + X(1+0.0275)^(-10)
=>X=2264.13 (wrong)

---

I figured out that it should be 1600(1+0.115)^-3.5 and i got the new answer which is 1555.50 but it was still wrong, can someone solve this?

 

[chabongden]

focal day is the day to calculate, if the payments are in the left side of the the FC, we use Future Value to calculate. If it's on the right, we use PV.

 

[tkhunny]

Why does it matter where the "Focal Day" is?

If you wish to move forward from "today", you will have to specify an interest rate for the $1,400. Is it given that it is the same as for the $1,600, or did you just assume that.

Your $1,555.50 might be a few cents off. Without any assumption regarding the $1400's interest rate, I have $1,554.71. Are you inappropriately rounding intermediate results?

 

[tkhunny]

You, too, have made the grand assumption about the interest rate on the $1,400.

 

[tkhunny]

You have also answered my question - Why does it matter where the Focus Date is? Good work.