Suppose [tex]$\$[/tex]45,000[tex]$ is invested by Stacy for 5 years in an account that earns interest monthly. Round the solutions to the nearest cent, if necessary.

1. Determine the future value of the account.
- Future Value $[/tex]=[tex]$ $[/tex]\square[tex]$

2. Determine the amount of interest earned in this account over the 5 years.
- Interest $[/tex]=[tex]$ $[/tex]\square[tex]$

Hint: Related Formulas

In the formulas below, $[/tex]A[tex]$ represents an account balance after $[/tex]t[tex]$ years, where $[/tex]P[tex]$ is the principal investment, $[/tex]r[tex]$ is the annual rate of interest (in decimal form), $[/tex]n[tex]$ is the number of compounding periods per year, and $[/tex]Y$ is the effective annual yield of the investment (in decimal form).

[tex]\[
A = P \left(1 + \frac{r}{n}\right)^{nt}
\][/tex]
[tex]\[
P = \frac{A}{\left(1 + \frac{r}{n}\right)^{nt}}
\][/tex]
[tex]\[
A = Pe^{rt}
\][/tex]
[tex]\[
Y = \left(1 + \frac{r}{n}\right)^n - 1
\][/tex]



Answer :

To find the future value of the investment and the interest earned, we use the compound interest formula:

[tex]\[ A = P \left(1 + \frac{r}{n}\right)^{nt} \][/tex]

Where:
- [tex]\( P \)[/tex] is the principal investment, which is [tex]\( \$45,000 \)[/tex].
- [tex]\( r \)[/tex] is the annual rate of interest in decimal form, which is [tex]\( 0.03 \)[/tex] (3%).
- [tex]\( n \)[/tex] is the number of compounding periods per year, which is [tex]\( 12 \)[/tex] (monthly).
- [tex]\( t \)[/tex] is the number of years the money is invested, which is [tex]\( 5 \)[/tex] years.

Substituting the given values into the formula, we get:

[tex]\[ A = 45000 \left(1 + \frac{0.03}{12}\right)^{12 \cdot 5} \][/tex]

First, calculate the monthly interest rate:

[tex]\[ \frac{0.03}{12} = 0.0025 \][/tex]

Next, calculate the exponent:

[tex]\[ 12 \times 5 = 60 \][/tex]

Thus, the formula becomes:

[tex]\[ A = 45000 \left(1 + 0.0025\right)^{60} \][/tex]

Calculate [tex]\( 1 + 0.0025 \)[/tex]:

[tex]\[ 1 + 0.0025 = 1.0025 \][/tex]

Now raise [tex]\( 1.0025 \)[/tex] to the power of [tex]\( 60 \)[/tex]:

Evaluating [tex]\( 1.0025^{60} \)[/tex] yields approximately [tex]\( 1.1638396 \)[/tex].

Now multiply this by the principal:

[tex]\[ A = 45000 \times 1.1638396 \approx 52272.76 \][/tex]

So the future value of the account is:

[tex]\[ \text{Future Value} = \$52,272.76 \][/tex]

To find the interest earned, we subtract the principal from the future value:

[tex]\[ \text{Interest} = A - P = 52272.76 - 45000 = 7272.76 \][/tex]

So the interest earned in the account over 5 years is:

[tex]\[ \text{Interest} = \$7,272.76 \][/tex]

In conclusion:
- The future value of the account is [tex]\( \$52,272.76 \)[/tex].
- The interest earned over 5 years is [tex]\( \$7,272.76 \)[/tex].