An investment of $9,875 earns 4.8% interest compounded monthly over 12 years. Approximately how much INTEREST is earned on the investment?

$17,546.55
$10,359.57
$484.57
$7,457.95

1 answer

To calculate the amount of interest earned on an investment with compounded interest, we can use the formula:

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

Where:

  • \( A \) = the future value of the investment/loan, including interest
  • \( P \) = the principal investment amount (initial deposit or loan amount)
  • \( r \) = the annual interest rate (decimal)
  • \( n \) = the number of times that interest is compounded per unit \( t \)
  • \( t \) = the time the money is invested or borrowed for, in years

Given:

  • \( P = 9,875 \)
  • \( r = 4.8% = 0.048 \)
  • \( n = 12 \) (monthly compounding)
  • \( t = 12 \)

Now we plug in the values:

\[ A = 9,875 \left(1 + \frac{0.048}{12}\right)^{12 \times 12} \]

Calculating inside the parentheses:

\[ 1 + \frac{0.048}{12} = 1 + 0.004 = 1.004 \]

Now calculate the exponent:

\[ 12 \times 12 = 144 \]

So we raise \( 1.004 \) to the power of 144:

\[ A = 9,875 \times (1.004)^{144} \]

Calculating \( (1.004)^{144} \):

Using a calculator:

\[ (1.004)^{144} \approx 1.7469 \]

Now, multiply by the principal:

\[ A \approx 9,875 \times 1.7469 \approx 17,266.34 \]

Now, to find the interest earned:

\[ \text{Interest} = A - P = 17,266.34 - 9,875 \approx 7,391.34 \]

Since this differs from the options given, let’s double-check both our calculations, rounding, and look closely:

  1. \( A \approx 17,266.34 \)
  2. Interest earn = \( 17,266.34 - 9,875 = 7,391.34 \)

None of the provided options are exact matches, but the closest option to this calculated interest is $7,457.95. Therefore, the approximate answer for the interest earned on the investment is:

$7,457.95