|  | 
| 
 
 
| Question 436853:  I have an investment of $1500.  After 4 years, it becomes $1700.  The number of compounding periods are 360.  What is my rate?
 I do not know how to go from my last step and find an answer.
 This is what I have so far, but do not know how to go from here.  It is very confusing to me.
 1700=1500(1+ r/360)^360 x 4
 1700=1500(1+ r/360)^1280
 ln(1+r/360)^1280=ln(17/15)
 1280ln(1+r/360)=ln(17/15)
 ln(1+r/360)=ln(17/15) all over 1280
 =1/1280ln(17/15)
 =ln(17/15)^1/1280
 r=360[((17/15)^1/1280)-1]
 This is where I do not understand how to go.  I have tried to divide 17 by 15 giving me 1.13, then taking that to the power of 1/1280, giving me 8.9, then subtracting 1, which gives me a -.9991145833.
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website!  I have an investment of $1500. After 4 years, it becomes $1700. The number of compounding periods are 360. What is my rate? --------------
 If in 4 years you are compounding 360 times, you are
 compounding 90 times each year.  That is "n" in the
 compounding formula.
 ------------------------------
 A(t) = P(1+(r/n))^(nt)
 -----
 1700 = 1500(1+r/90))^(90*4)
 -------------------------
 17/15 = (1+(r/90)^(360)
 ---
 Take the 360 root of both sides to get:
 1+(r/90) = 1.000348
 r/90 = 0.000348
 rate = 0.0313
 rate = 3.13%
 =====================
 Cheers,
 Stan H.
 =====================
 | 
  
 | 
 |  |  |