Tara invests $2,000 into a continuously compounding account with an annual interest rate of 5%. Use the formula P (t) = 2,000e^u.u5t to determine how much money will be in her account after 15 years.

answer choices:

$1,060.88

B
$4,234.00

C
$15,243.98

D
$16,345.01

1 answer

To calculate the amount of money in Tara's account after 15 years with continuous compounding, we can use the formula for continuous compounding:

\[ P(t) = P_0 e^{rt} \]

where:

  • \( P(t) \) is the amount in the account at time \( t \),
  • \( P_0 \) is the initial principal (the initial amount of money),
  • \( r \) is the annual interest rate (as a decimal),
  • \( t \) is the time in years,
  • \( e \) is the base of the natural logarithm (approximately equal to 2.71828).

In this case:

  • \( P_0 = 2000 \),
  • \( r = 0.05 \) (5%),
  • \( t = 15 \).

Now we substitute these values into the formula:

\[ P(15) = 2000 e^{0.05 \cdot 15} \]

Calculating the exponent:

\[ 0.05 \cdot 15 = 0.75 \]

Now we calculate \( e^{0.75} \):

\[ e^{0.75} \approx 2.117 \]

Then we can compute \( P(15) \):

\[ P(15) = 2000 \cdot 2.117 \approx 4234.00 \]

So, the amount of money in her account after 15 years is approximately $4,234.00.

The correct answer is B. $4,234.00.