1. **State the problem:** We want to find the nominal interest rate compounded quarterly that grows $22,000 to $37,984.34 in 20 years.
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 amount
- $r$ is the nominal annual interest rate (decimal)
- $n$ is the number of compounding periods per year
- $t$ is the number of years
3. **Given values:**
- $A = 37984.34$
- $P = 22000$
- $n = 4$ (quarterly compounding)
- $t = 20$
4. **Plug values into the formula:**
$$37984.34 = 22000 \left(1 + \frac{r}{4}\right)^{4 \times 20} = 22000 \left(1 + \frac{r}{4}\right)^{80}$$
5. **Isolate the compound factor:**
$$\frac{37984.34}{22000} = \left(1 + \frac{r}{4}\right)^{80}$$
$$1.72656 = \left(1 + \frac{r}{4}\right)^{80}$$
6. **Take the 80th root of both sides:**
$$\sqrt[80]{1.72656} = 1 + \frac{r}{4}$$
7. **Calculate the 80th root:**
$$1 + \frac{r}{4} = 1.007\quad (rounded)$$
8. **Solve for $r$:**
$$\frac{r}{4} = 1.007 - 1 = 0.007$$
$$r = 0.007 \times 4 = 0.028$$
9. **Convert to percentage:**
$$r = 0.028 \times 100 = 2.8\%$$
**Final answer:** The nominal interest rate compounded quarterly is **2.8%**.
Nominal Interest Rate 16Fa48
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.