To start a new business Beth deposits ​$2000 at the end of each​ six-month period in an account that pays 8​%, compounded semiannually. How much will she have at the end of 9 ​years?

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Part 1
At the end of 9 ​years, Beth will have approximately ​$
  
enter your response here.
​(Do not round until the final answer. Then round to the nearest hundredth as​ needed.)

1 answer

To find out how much Beth will have at the end of 9 years by depositing $2000 at the end of each six-month period in an account that pays 8% interest, compounded semiannually, we can use the future value of an ordinary annuity formula:

\[ FV = P \times \frac{(1 + r)^n - 1}{r} \]

Where:

  • \( FV \) = future value of the annuity
  • \( P \) = payment amount per period
  • \( r \) = interest rate per period
  • \( n \) = total number of payments

Given:

  • \( P = 2000 \)
  • Annual interest rate = 8%, so the semiannual interest rate \( r = \frac{0.08}{2} = 0.04 \)
  • Total time = 9 years, with 2 periods per year, gives us \( n = 9 \times 2 = 18 \)

Now, plug the values into the formula:

\[ FV = 2000 \times \frac{(1 + 0.04)^{18} - 1}{0.04} \]

Calculating \( (1 + 0.04)^{18} \):

\[ (1 + 0.04)^{18} = (1.04)^{18} \approx 1.868246 \]

Now substitute back:

\[ FV = 2000 \times \frac{1.868246 - 1}{0.04} \] \[ FV = 2000 \times \frac{0.868246}{0.04} \] \[ FV = 2000 \times 21.70615 \approx 43412.30 \]

Thus, the total amount that Beth will have at the end of 9 years is approximately $43,412.30.