document.write( "Question 1205675: Every week you put $10 in an investment that pays 10.4% interest, compounded weekly. After 35 years how much would you put into the investment? \n" ); document.write( "

Algebra.Com's Answer #842638 by ikleyn(52909) $\"\"$ $\"About$

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\n" ); document.write( "Every week you put $10 in an investment that pays 10.4% interest, compounded weekly.
\n" ); document.write( "After 35 years how much would you put into the investment?
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\n" ); document.write( "\n" ); document.write( "        In his solution, @Theo mistakenly used the annual interest rate 0.1045,\r
\n" ); document.write( "\n" ); document.write( "        while the given value of the annual interest rate in this problem is 0.104.\r
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\n" ); document.write( "\n" ); document.write( "        I came to show you calculations/solution for the given value of the annual interest.\r
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document.write( "Although the problem does not say it explicitly, I will assume that the investment\r\n" );
document.write( "is made at the end of each week.\r\n" );
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document.write( "Then it is a classic ordinary annuity saving plan.\r\n" );
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document.write( "The formula for the Ordinary Annuity saving plan is\r\n" );
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document.write( "f = ,\r\n" );
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document.write( "f is the future value\r\n" );
document.write( "p is the weekly payment\r\n" );
document.write( "r is the interest rate per time period\r\n" );
document.write( "n is the number of time periods.\r\n" );
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document.write( "In your problem:\r\n" );
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document.write( "time periods are weeks.\r\n" );
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document.write( "p = 10 dollars  \r\n" );
document.write( "r = 0.104/52  interest per week\r\n" );
document.write( "n = 35 * 52 = 1820 weeks   (counting 52 weeks in the year)\r\n" );
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document.write( "formula becomes f =  = 184768.09.\r\n" );
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document.write( "You will have $184768.09  in your saving account in 35 years.\r\n" );
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document.write( "Interesting, that your total direct investment will be only  $10*52*35 = $18200.\r\n" );
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document.write( "The rest is what the account will earn due to compounding.\r\n" );
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\n" ); document.write( "\n" ); document.write( "On Ordinary Annuity saving plans see the lessons\r
\n" ); document.write( "\n" ); document.write( " - Ordinary Annuity saving plans and geometric progressions\r
\n" ); document.write( "\n" ); document.write( " - Solved problems on Ordinary Annuity saving plans \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "The lessons contain EVERYTHING you need to know about this subject, in clear and compact form.\r
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\n" ); document.write( "\n" ); document.write( "When you learn from these lessons, you will be able to do similar calculations in semi-automatic mode.\r
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\n" ); document.write( "\n" ); document.write( "To make such complicated calculations as they are in this problem,
\n" ); document.write( "you should have/use an appropriate calculator for such long formulas.\r
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\n" ); document.write( "\n" ); document.write( "Ideal choice is MS Excel, if you have it in your computer.\r
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\n" ); document.write( "\n" ); document.write( "Then you write a formula in a text editor, copy-paste it
\n" ); document.write( "into an Excel work-sheet cell and click \"enter\" - the result is ready
\n" ); document.write( "instantaneously.\r
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\n" ); document.write( "\n" ); document.write( "If you have no MS Excel in your computer, you may find similar
\n" ); document.write( "free of charge calculators in the Internet. One such calculator is\r
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\n" ); document.write( "\n" ); document.write( "www.desmos.com/calculator\r
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\n" ); document.write( "\n" ); document.write( "It allows you to do the same thing: you write a formula in a text editor,
\n" ); document.write( "copy-paste it into this calculator and click \"enter\" - the result is ready
\n" ); document.write( "instantaneously.\r
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