Carl Frederickson is 25 years old and decides to invest $5000 in a savings account that compounds monthly rate of 14%. After 15 years, how much is in the account?

1 answer

To calculate the future value of an investment with compound interest, you can use the formula:

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

where:

  • \(A\) is the amount of money accumulated 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 for.

In this case:

  • \(P = 5000\)
  • \(r = 0.14\) (14% as a decimal)
  • \(n = 12\) (monthly compounding)
  • \(t = 15\)

Now, we can plug these values into the formula:

\[ A = 5000 \left(1 + \frac{0.14}{12}\right)^{12 \times 15} \]

First, calculate \(\frac{r}{n}\):

\[ \frac{0.14}{12} \approx 0.01166667 \]

Now calculate \(nt\):

\[ nt = 12 \times 15 = 180 \]

Now we can substitute these values into the formula:

\[ A = 5000 \left(1 + 0.01166667\right)^{180} \]

This simplifies to:

\[ A = 5000 \left(1.01166667\right)^{180} \]

Now we calculate \((1.01166667)^{180}\):

\[ (1.01166667)^{180} \approx 5.188652236 \]

Now calculate \(A\):

\[ A \approx 5000 \times 5.188652236 \approx 25943.26 \]

So, after 15 years, Carl Frederickson will have approximately $25,943.26 in the account.