document.write( "Question 724057: How much money must be deposited now in an account paying 8% annual interest, compounded quarterly, to have a balance of $1,000 after 10 years? \n" ); document.write( "
Algebra.Com's Answer #443570 by Jstrasner(112)![]() ![]() You can put this solution on YOUR website! Hey,\r \n" ); document.write( "\n" ); document.write( "So for this one, we need to create a formula for calculating the amount. A normal compounded interest formula looks like this:\r \n" ); document.write( "\n" ); document.write( "A = B ( 1 + r ) ^n \r \n" ); document.write( "\n" ); document.write( "Where A is the ending amount of money, in this case $1000. B is the beginning amount of money, in this case x because we don't know. Little r is the rate, in this case .08 (or 8%). Little n is the number of years the money is in the bank, in this case 10 years. This would work, HOWEVER, the interest is compounded quarterly, which means 4 times a year. Therefore the formula is change to look like this:\r \n" ); document.write( "\n" ); document.write( "A = B ( 1 + r/t ) ^ (n)(t) \r \n" ); document.write( "\n" ); document.write( "Where everything is the same except that we divide the rate (r) by the number of times a year the interest is made (t) and then instead of just taking that amount to the exponent of n, we need to first multiply n by the number of times per year (t). So this is what this problem would look like:\r \n" ); document.write( "\n" ); document.write( "$1,000 = x ( 1 + .08/4 ) ^ (10)(4) \r \n" ); document.write( "\n" ); document.write( "First we solve what is in the parentheses:\r \n" ); document.write( "\n" ); document.write( " 1 + .08/4 => 1 + .02 => 1.02 \r \n" ); document.write( "\n" ); document.write( "Then we multiply the exponents together:\r \n" ); document.write( "\n" ); document.write( " (10)(4) => 40 \r \n" ); document.write( "\n" ); document.write( "Then we take 1.02 ^ 40 => 2.208... \r \n" ); document.write( "\n" ); document.write( "Now we have to isolate the x so we can solve for it. In order to do this, we need to get rid of the 2.208 by dividing both sides by 2.208 :\r \n" ); document.write( "\n" ); document.write( " $1000/2.208 = x (2.208)/2.208 => 452.8985..... = x \r \n" ); document.write( "\n" ); document.write( "And now we have the answer.\r \n" ); document.write( "\n" ); document.write( "If we deposit around $453 into a bank with compound interest of 8% quarterly, we will have $1000 after 10 years. \r \n" ); document.write( "\n" ); document.write( "Again the answer is $453. \r \n" ); document.write( "\n" ); document.write( "I hope this helps! \n" ); document.write( " |