document.write( "Question 1167429: Kenneth ran into some money and decides to invest it for retirement. He has $75,000 to invest over
\n" ); document.write( "40 years. Find the effective rates given:
\n" ); document.write( "(a) 4.5% growth compounded monthly.
\n" ); document.write( "(b) 4.45% growth compounded continuously.
\n" ); document.write( "(c) Should Kenneth invest in option (a) or option (b)? Why?
\n" ); document.write( "

Algebra.Com's Answer #792090 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
the present value of the investment is 75,000.
\n" ); document.write( "the investment period is 40 years.
\n" ); document.write( "the discrete compounding growth rate is 4.5% compounded monthly.
\n" ); document.write( "the continuous compounding growth rate is 4.45% compounded continuously.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the formula for discrete compounding is f = p * (1 + r) ^ n\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f is the future value
\n" ); document.write( "p is the present value
\n" ); document.write( "r is the interest rate per time period
\n" ); document.write( "n is the number of time periods.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the formula for continuous compounding is f = p * e ^ (r * t)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f is the future value
\n" ); document.write( "p is the present value
\n" ); document.write( "r is the interest rate per time period
\n" ); document.write( "t is the number of time periods.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "when your initial investment is 75,000 and your time period is 40 years, your future value will be calculated as follows:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with discrete monthly compounding, you get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f = 75000 * (1 + .045/12) ^ (40 * 12) = 452198.6287.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with continuous compounding, you get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f = 75000 * e ^ (.0445 * 40) = 444739.2314\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4.5% compounded monthly gives you more future value than 4.45% compounded continuously.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "if you look at the effective annual rates, you will see why this occurs.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with discrete compounding, the effective annual growth factor becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f = (1 + .045/12) ^ 12 = 1.045939825.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with continuous compounding, the effective annual growth factor becomes:
\n" ); document.write( "f = e ^ (.0445) = 1.045504977.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with discrete compounding, 75,000 * 1.045939825 ^ 40 = 452198.6287\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "with continuous compounding, 75,000 * 1.045504977 = 444739.2314\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the effective annual growth rate tells you which will give you a greater future value.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the answers to your questions are:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(a) 4.5% growth compounded monthly.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "effective annual growth rate is .045939825 or 4.5939825%\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(b) 4.45% growth compounded continuously.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "effective annual growth rate is .045504977 or 4.5504977%\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(c) Should Kenneth invest in option (a) or option (b)? Why?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "invest in option a because the effective annual interest rate is higher.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );