Question 1146477
the investment is 20 dollars at the end of each month for 3 years = 3 * 12 = 36 months.
the interest rate if 8.2% per month compounded monthly = 8.2% / 12 = .6833333333...% per month.
it's a never ending decimal, but carrying out the 3's for 8 positions is usually sufficient.


using the online calculator at <a href = "https://arachnoid.com/finance/" target = "_blank">https://arachnoid.com/finance/</a>, i get a future value of $813.16 after i click on FV.


my inputs and outputs are shown below, using this online calculator.


<img src = "http://theo.x10hosting.com/2019/100601.jpg" alt="$$$" >


<img src = "http://theo.x10hosting.com/2019/100602.jpg" alt="$$$" >