Erica opened a savings account and deposited $200.00 as principal. The account earns 10% interest, compounded annually. What is the balance after 6 years?

Use the formula A=P (1+r/n)^nt, where A is the balance (final amount), P is the principal (starting amount), r is the interest rate expressed as a decimal, n is the number of times per year that the interest is compounded, and t is the time in years.
Round your answer to the nearest cent.

1 answer

To calculate the balance after 6 years for Erica's savings account, we can use the formula for compound interest:

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

Where:

  • \( A \) is the balance after time \( t \),
  • \( P \) is the principal amount (the initial deposit),
  • \( r \) is the annual interest rate (as a decimal),
  • \( n \) is the number of times interest is compounded per year,
  • \( t \) is the number of years.

Given the information:

  • \( P = 200.00 \)
  • \( r = 10% = 0.10 \)
  • \( n = 1 \) (interest is compounded annually)
  • \( t = 6 \)

Now we can substitute these values into the formula:

\[ A = 200 \left(1 + \frac{0.10}{1}\right)^{1 \times 6} \]

This simplifies to:

\[ A = 200 \left(1 + 0.10\right)^{6} = 200 \left(1.10\right)^{6} \]

Next, we calculate \( (1.10)^{6} \):

\[ (1.10)^{6} \approx 1.771561 \]

Now multiply this by the principal:

\[ A \approx 200 \times 1.771561 \approx 354.3122 \]

Finally, rounding to the nearest cent, the balance after 6 years will be:

\[ \boxed{354.31} \]