Clara puts $700.00 into an account to use for school expenses. The account earns 6% interest, compounded continuously. How much will be in the account after 6 years?

Use the formula A=Pert, where A is the balance (final amount), P is the principal (starting amount), e is the base of natural logarithms (≈2.71828), r is the interest rate expressed as a decimal, and t is the time in years.
Round your answer to the nearest cent.
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1 answer

To calculate the amount in the account after 6 years using the formula for continuous compounding, we will use the formula:

\[ A = P e^{rt} \]

Where:

  • \(A\) is the balance after time \(t\),
  • \(P\) is the principal amount (initial investment),
  • \(e\) is the base of the natural logarithm (approximately 2.71828),
  • \(r\) is the annual interest rate (as a decimal),
  • \(t\) is the time in years.

From the problem:

  • \(P = 700.00\)
  • \(r = 0.06\) (since 6% = 0.06)
  • \(t = 6\)

Now, substitute the values into the formula:

\[ A = 700 \cdot e^{0.06 \cdot 6} \]

Calculate the exponent first:

\[ 0.06 \cdot 6 = 0.36 \]

Now calculate \(e^{0.36}\):

Using a calculator, \(e^{0.36} \approx 1.4333\) (rounded to four decimal places).

Now substitute back:

\[ A = 700 \cdot 1.4333 \approx 1003.31 \]

Finally, rounding to the nearest cent:

\[ A \approx 1003.31 \]

Thus, the amount in the account after 6 years will be $1003.31.