Suppose that $2000 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 calculate the total amount after 4 years when $2000 is invested at a rate of 3.1% compounded quarterly, we will use the compound interest formula:

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

Where:

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

Given:

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

Now, let's substitute these values into the formula:

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

Calculating \( \frac{r}{n} \):

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

Now, compute \( 1 + \frac{r}{n} \):

\[ 1 + 0.00775 = 1.00775 \]

Next, calculate \( nt \):

\[ nt = 4 \times 4 = 16 \]

Now substitute back into the formula:

\[ A = 2000 \left(1.00775\right)^{16} \]

Calculating \( (1.00775)^{16} \):

\[ (1.00775)^{16} \approx 1.130325186 \]

Now, we will find \( A \):

\[ A \approx 2000 \times 1.130325186 \approx 2260.650372 \]

Finally, rounding to the nearest cent:

\[ A \approx 2260.65 \]

Thus, the total amount after 4 years is

\[ \boxed{2260.65} \]