How long does it take $1125 to triple if it is invested at 7% interest, compounded quarterly? round your answer to the nearest tenth?

To solve this problem you must apply the proccedure shown below:
 1. You have to apply the following formula:
 FV=PV[1+(i/n)]^4t
 FV=3x1125
 FV=3375
 PV=1125
 i=0.07
 n=4
 2. When you substitute the values into the formula, you obtain:
 3375=1125[1+(0.07/4)]^4t
 3. Now, you must solve for t, as following:
 3375/1125=1+(0.07/4)^4t
 3=(1.0175)^4t
 log(3)=log(1.0175)^4t
 log(3)=4t(log(1.0175))
 4t=63.32
 t=15.83 years
 The answer is: 15.83 years.

What the heck i didn’t know