1. **State the problem:** Sophia wants to find the initial investment amount (principal $P$) needed to reach a future value $A = 1450$ in 14 years with an interest rate of 3.4% compounded monthly.
2. **Formula used:** The compound interest formula is
$$A = P \left(1 + \frac{r}{n}\right)^{nt}$$
where:
- $A$ is the amount of money accumulated after $t$ years, including interest.
- $P$ is the principal (initial investment).
- $r$ is the annual interest rate (decimal).
- $n$ is the number of times interest is compounded per year.
- $t$ is the time the money is invested for in years.
3. **Given values:**
- $A = 1450$
- $r = 0.034$
- $n = 12$ (monthly compounding)
- $t = 14$
4. **Rearrange the formula to solve for $P$:**
$$P = \frac{A}{\left(1 + \frac{r}{n}\right)^{nt}}$$
5. **Calculate the denominator:**
$$1 + \frac{r}{n} = 1 + \frac{0.034}{12} = 1 + 0.0028333 = 1.0028333$$
$$nt = 12 \times 14 = 168$$
6. **Calculate the compound factor:**
$$\left(1.0028333\right)^{168} \approx 1.5683$$
7. **Calculate $P$:**
$$P = \frac{1450}{1.5683}$$
8. **Simplify with cancellation:**
$$P = \frac{1450}{\cancel{1.5683}}$$
9. **Final calculation:**
$$P \approx 924.88$$
10. **Answer:** Sophia needs to invest approximately **925** dollars to reach 1450 dollars in 14 years with 3.4% interest compounded monthly.
Compound Interest 84A4Da
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