# Annuity compound interest

How much would u have after investing $150 every month for ten years in an account that pays 4.25% compounded monthly. So i know the following information 0.0425/ 12 - 0.0035 interest paid 120 times I am awaure of the formula, Sn = A (r^n-1) / 1-r but it my result does not seem to make sense. Thanks • Jan 10th 2011, 05:07 PM dwsmith I usually use the finance feature of my calculator. I would input PMT = 150, n = 120, i = 4.25/12, and then click compute on FV option. • Jan 10th 2011, 05:08 PM Chr2010 ok thanks, I will try and find on online • Jan 10th 2011, 05:09 PM dwsmith Do you have a Ti - 83, 84, or 89? • Jan 10th 2011, 05:12 PM Chr2010 no unfortunately not • Jan 10th 2011, 05:14 PM dwsmith Ti -BA II Plus? • Jan 10th 2011, 05:16 PM Chr2010 lol nope no calculators • Jan 10th 2011, 05:19 PM dwsmith $\displaystyle \mbox{FV}_{\mbox{annuity}}=\frac{\left(1+\frac{i}{ n}\right)^{n*t}-1}{\frac{i}{n}}*\mbox{PMT}=\frac{\left(1+\frac{.04 25}{12}\right)^{120}-1}{\frac{.0425}{12}}*150$ • Jan 10th 2011, 05:30 PM Chr2010 thanks! • Jan 10th 2011, 05:33 PM Chr2010 i got 148 ?!?!? • Jan 10th 2011, 05:37 PM dwsmith Quote: Originally Posted by Chr2010 i got 148 ?!?!? Noooo. FV =$22,381.09