Suppose you deposit $1,005.00 into an account 5.00 years from today that earns 10.00%. It will be worth $1,931.00 _____ years from today.

1 answer

To find out how many years from today the investment of $1,005.00 will grow to $1,931.00, we can use the future value formula:

\[ FV = PV \times (1 + r)^n \]

Where:

  • \( FV \) is the future value of the investment,
  • \( PV \) is the present value or initial deposit,
  • \( r \) is the annual interest rate (as a decimal),
  • \( n \) is the number of years the money is invested.

In this problem:

  • \( FV = 1,931.00 \)
  • \( PV = 1,005.00 \)
  • \( r = 10% = 0.10 \)

We can rearrange the formula to solve for \( n \):

\[ n = \frac{\log(FV / PV)}{\log(1 + r)} \]

Substituting the values:

\[ n = \frac{\log(1,931.00 / 1,005.00)}{\log(1 + 0.10)} \]

Calculating the fraction inside the logarithm:

\[ \frac{1,931.00}{1,005.00} \approx 1.920 \]

Now calculating the logs:

\[ n = \frac{\log(1.920)}{\log(1.10)} \]

Using a calculator to find the logarithms:

  • \( \log(1.920) \approx 0.283 \)
  • \( \log(1.10) \approx 0.0414 \)

Now we compute \( n \):

\[ n \approx \frac{0.283}{0.0414} \approx 6.83 \]

Thus, the time it takes for the account to grow from $1,005.00 to $1,931.00 is approximately 6.83 years.

Since the deposit is made 5.00 years from today, the total time from today will be:

\[ 6.83 + 5 = 11.83 \text{ years} \]

So the answer is:

It will be worth $1,931.00 in approximately 11.83 years from today.