A person places [tex]$\$[/tex] 6650[tex]$ in an investment account earning an annual rate of $[/tex]7.2 \%[tex]$, compounded continuously. Using the formula $[/tex]V = P e^{rt}[tex]$, where $[/tex]V[tex]$ is the value of the account in $[/tex]t[tex]$ years, $[/tex]P[tex]$ is the principal initially invested, $[/tex]e[tex]$ is the base of the natural logarithm, and $[/tex]r$ is the rate of interest, determine the amount of money, to the nearest cent, in the account after 14 years.



Answer :

To determine the amount of money in the investment account after 14 years, given the continuous compounding interest formula [tex]\( V = P e^{rt} \)[/tex], where:

- [tex]\( P \)[/tex] is the initial investment,
- [tex]\( r \)[/tex] is the annual interest rate,
- [tex]\( t \)[/tex] is the number of years,
- [tex]\( e \)[/tex] is the base of the natural logarithm.

Let's use the values provided:

1. The initial investment [tex]\( P = \$6650 \)[/tex].
2. The annual interest rate [tex]\( r = 7.2\% = 0.072 \)[/tex] (converted to a decimal).
3. The number of years [tex]\( t = 14 \)[/tex].

First, we substitute these values into the formula:

[tex]\[ V = 6650 \times e^{0.072 \times 14} \][/tex]

Next, we calculate the exponent:

[tex]\[ 0.072 \times 14 = 1.008 \][/tex]

So, the expression becomes:

[tex]\[ V = 6650 \times e^{1.008} \][/tex]

Using the value of [tex]\( e \)[/tex] (approximately 2.71828), we compute [tex]\( e^{1.008} \)[/tex]:

[tex]\[ e^{1.008} \approx 2.739 \][/tex]

Now multiply the initial investment by this exponential factor:

[tex]\[ V = 6650 \times 2.739 \][/tex]

Perform the multiplication:

[tex]\[ V \approx 18221.77 \][/tex]

Therefore, the amount of money in the account after 14 years, rounded to the nearest cent, is:

[tex]\[ \$18221.77 \][/tex]