Suppose that S2000 is invested at a rate of 3.1%, compounded quarterly. Assuming that no withdrawals are made, find the total amount after 4 years.

Do not round any intermediate computations, and round your answer to the nearest cent.

1 answer

To find the total amount after 4 years of investment of S2000 at an interest rate of 3.1% compounded quarterly, we can use the formula for compound interest:

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

Where:

  • \(A\) is the amount of money accumulated after n years, including interest.
  • \(P\) is the principal amount (the initial amount of money).
  • \(r\) is the annual interest rate (decimal).
  • \(n\) is the number of times interest is compounded per year.
  • \(t\) is the number of years the money is invested for.

Given:

  • \(P = 2000\)
  • \(r = 3.1% = 0.031\)
  • \(n = 4\) (since it is compounded quarterly)
  • \(t = 4\)

Plugging in the values:

\[ A = 2000 \left(1 + \frac{0.031}{4}\right)^{4 \times 4} \]

Now, calculate the individual components:

  1. Calculate the quarterly interest rate:

\[ \frac{0.031}{4} = 0.00775 \]

  1. Calculate the total number of compounding periods:

\[ n \times t = 4 \times 4 = 16 \]

  1. Substitute these values back into the formula:

\[ A = 2000 \left(1 + 0.00775\right)^{16} \]

  1. Calculate \(1 + 0.00775\):

\[ 1 + 0.00775 = 1.00775 \]

  1. Raise this to the power of 16:

\[ 1.00775^{16} \approx 1.127304 \]

  1. Now multiply by the principal:

\[ A \approx 2000 \times 1.127304 \approx 2254.608 \]

  1. Finally, round the answer to the nearest cent:

\[ A \approx 2254.61 \]

Thus, the total amount after 4 years is $2254.61.