Question: How much money should be deposited today in an account that earns 4.5% compounded monthly so that it will accumulate to $13,000 in 2 years?
1. **State the problem:** We want to find the present value (the amount to deposit today) that will grow to $13,000 in 2 years with an interest rate of 4.5% compounded monthly.
2. **Formula used:** The compound interest formula is $$A = P \left(1 + \frac{r}{n}\right)^{nt}$$ where:
- $A$ is the amount accumulated after $t$ years,
- $P$ is the principal (initial deposit),
- $r$ is the annual interest rate (decimal),
- $n$ is the number of compounding periods per year,
- $t$ is the time in years.
3. **Given values:**
- $A = 13000$
- $r = 0.045$
- $n = 12$ (monthly compounding)
- $t = 2$
4. **Rearrange the formula to solve for $P$:**
$$P = \frac{A}{\left(1 + \frac{r}{n}\right)^{nt}}$$
5. **Substitute the values:**
$$P = \frac{13000}{\left(1 + \frac{0.045}{12}\right)^{12 \times 2}} = \frac{13000}{\left(1 + 0.00375\right)^{24}} = \frac{13000}{(1.00375)^{24}}$$
6. **Calculate the denominator:**
$$(1.00375)^{24} \approx 1.093443$$
7. **Calculate $P$:**
$$P = \frac{13000}{1.093443} \approx 11883.68$$
**Final answer:** The amount to deposit today is approximately **11883.68**.