document.write( "Question 1207429: Keys Company has a target of establishing a fund of$50 OOO. If$10 OOO is deposited at the end of every six months, and the fund earns interest at 4% compounded quarterly, how long will it take to reach the target? \n" ); document.write( "
Algebra.Com's Answer #845274 by ikleyn(52834)\"\" \"About 
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\n" ); document.write( "Keys Company has a target of establishing a fund of $50,000. If $10,000 is deposited
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\n" ); document.write( "how long will it take to reach the target?
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document.write( "It is a non-traditional accumulative saving plan with $10,000 deposited semi-annually and compounded \r\n" );
document.write( "quarterly at 4% per annum. \r\n" );
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document.write( "It means that the quarterly effective rate is  0.04/4 = 0.01 and the equivalent\r\n" );
document.write( "semi-annual effective rate is \"%281%2B0.01%29%5E2\" = \"1.01%5E2\" = 1.0201.\r\n" );
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document.write( "    |  So, this non-traditional accumulative saving plan is equivalent  |\r\n" );
document.write( "    |   to the ordinary annuity with semi-annual deposits of $10,000    |\r\n" );
document.write( "    |   and the semi-annual effective rate of compounding r = 1.0201.   |\r\n" );
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document.write( "Now use the general formula for a classic Ordinary Annuity saving plan\r\n" );
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document.write( "    FV = \"P%2A%28%28%281%2Br%29%5En-1%29%2Fr%29\",    (1)\r\n" );
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document.write( "where  FV is the future value of the annuity;  P is the semi-annual deposit; r is the semi-annual \r\n" );
document.write( "effective percentage yield presented as a decimal; n is the number of deposits.\r\n" );
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document.write( "Under the given conditions, P = 10000;  r = 0.0201.  So, according to (1), the formula for\r\n" );
document.write( "the future value is\r\n" );
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document.write( "    FV = \"10000%2A%28%28%281%2B0.0201%29%5En-1%29%2F0.0201%29\".\r\n" );
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document.write( "So, we should find n, the number of deposits (or the number of semi-annual periods)  from this equation\r\n" );
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document.write( "    50000 = \"10000%2A%28%281.0201%5En-1%29%2F0.0201%29\".\r\n" );
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document.write( "Simplify it by dividing both sides by 10000\r\n" );
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document.write( "    \"50000%2F10000\" = \"%28%281.0201%5En-1%29%2F0.0201%29\",\r\n" );
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document.write( "or\r\n" );
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document.write( "    5 = \"%28%281.0201%5En-1%29%2F0.0201%29\".\r\n" );
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document.write( "Simplify it further, step by step\r\n" );
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document.write( "    5*0.0201 = \"1.0201%5En-1\",\r\n" );
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document.write( "    0.1005 = \"1.0201%5En-1\",\r\n" );
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document.write( "    0.1005 + 1 = \"1.0201%5En\",\r\n" );
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document.write( "    1.1005 = \"1.0201%5En\".\r\n" );
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document.write( "Take logarithm base 10 of both sides\r\n" );
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document.write( "    log(1.1005) = n*log(1.0201)\r\n" );
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document.write( "and find n\r\n" );
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document.write( "    n = \"log%28%281.1005%29%29%2Flog%28%281.0201%29%29\" = 4.81  (approximately).\r\n" );
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document.write( "Finally, round the decimal value of 4.81 to the closest GREATER integer value of 5 \r\n" );
document.write( "in order for the bank be in position to complete the last semi-annual compounding.\r\n" );
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document.write( "At this point, the solution is complete.\r\n" );
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document.write( "The ANSWER is: 5 semi-annual periods are needed.\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
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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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