document.write( "Question 1195829: How long will it take to save ​$12500 by making deposits of ​$90 at the end of every month into an account earning interest at ​%3.9 compounded annually \n" ); document.write( "
Algebra.Com's Answer #828390 by Theo(13342)\"\" \"About 
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normally, deposits monthly uses interest rate compounded monthly.
\n" ); document.write( "you asked for 3.9% compounded annually.
\n" ); document.write( "that means your effective interest rate is 3.9% per year.
\n" ); document.write( "that means your effective growth factor is 1.039 per year.
\n" ); document.write( "the equivalent monthly growth factor is (1.039)^(1/12) = 1.003193314 per month.
\n" ); document.write( "that means your equivalent monthly growth rate = .3193314% per month.
\n" ); document.write( "that ^ 12 = 1.039, which matches your effective annual growth factor.
\n" ); document.write( "using the calculator at https://arachnoid.com/finance/, i get the following.
\n" ); document.write( "
\n" ); document.write( "inputs are all fields except np.
\n" ); document.write( "output is np = 115.14.
\n" ); document.write( "divide that by 12 to get 9.595 years.
\n" ); document.write( "note that, if the annual growth rate was compounded monthly, then the monthly growh rate would be 3.9/12 = .325%
\n" ); document.write( "that's slightly higher than .3183314/% per month which will require slightly less number of months to get to the same future value of 12500.
\n" ); document.write( "results are shown below:
\n" ); document.write( "
\n" ); document.write( "once again, inputs are all fields except np.
\n" ); document.write( "output is np = 114.81 months.
\n" ); document.write( "divide that by 12 to get 9.5675 years.
\n" ); document.write( "assuming 3.9% per year compounded annually, your solution is 115.14 months or 9.595 years.
\n" ); document.write( "let me know if you have any questions.
\n" ); document.write( "theo\r
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