1. **State the problem:** Sarah wants to find the initial investment amount (principal $P$) that will grow to $1030$ in $5$ years with an interest rate of $5.3\%$ compounded quarterly.
2. **Formula used:** The compound interest formula is
$$A = P \left(1 + \frac{r}{n}\right)^{nt}$$
where:
- $A$ is the amount after time $t$
- $P$ is the principal (initial investment)
- $r$ is the annual interest rate (decimal)
- $n$ is the number of compounding periods per year
- $t$ is the time in years
3. **Identify values:**
- $A = 1030$
- $r = 0.053$
- $n = 4$ (quarterly compounding)
- $t = 5$
4. **Substitute values into the formula:**
$$1030 = P \left(1 + \frac{0.053}{4}\right)^{4 \times 5}$$
5. **Simplify inside the parentheses:**
$$1 + \frac{0.053}{4} = 1 + 0.01325 = 1.01325$$
6. **Calculate the exponent:**
$$4 \times 5 = 20$$
7. **Rewrite the equation:**
$$1030 = P \times (1.01325)^{20}$$
8. **Calculate $(1.01325)^{20}$:**
$$ (1.01325)^{20} \approx 1.29744 $$
9. **Solve for $P$:**
$$P = \frac{1030}{1.29744}$$
10. **Show cancellation step:**
$$P = \frac{1030}{\cancel{1.29744}} \times \frac{\cancel{1}}{1} = \frac{1030}{1.29744}$$
11. **Calculate $P$:**
$$P \approx 793.68$$
12. **Round to nearest dollar:**
$$P \approx 794$$
**Final answer:** Sarah needs to invest approximately **794** dollars to reach 1030 dollars in 5 years with 5.3% interest compounded quarterly.
Compound Interest 9C3865
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