Compound Interest B0382B
1. **State the problem:** Calculate the amount of P55000 compounded quarterly at an annual interest rate of 12.15% for 9 years.
2. **Formula used:** The compound interest formula is $$A = P \left(1 + \frac{r}{n}\right)^{nt}$$ where:
- $A$ is the amount after interest
- $P$ is the principal amount
- $r$ is the annual interest rate (decimal)
- $n$ is the number of times interest is compounded per year
- $t$ is the time in years
3. **Identify values:**
- $P = 55000$
- $r = 0.1215$
- $n = 4$ (quarterly compounding)
- $t = 9$
4. **Calculate the amount:**
$$A = 55000 \left(1 + \frac{0.1215}{4}\right)^{4 \times 9} = 55000 \left(1 + 0.030375\right)^{36} = 55000 \times (1.030375)^{36}$$
5. **Evaluate the power:**
Calculate $(1.030375)^{36}$ using a calculator:
$$ (1.030375)^{36} \approx 2.41414 $$
6. **Multiply to find $A$:**
$$ A = 55000 \times 2.41414 = 132777.7 $$
7. **Interpretation:** The amount after 9 years is approximately P132777.7.
Since the question asks for the interest earned or the amount minus principal:
8. **Calculate interest earned:**
$$ \text{Interest} = A - P = 132777.7 - 55000 = 77777.7 $$
The options given (P18729.73, P18792.73, P18279.73, P18297.73) do not match the total amount or interest calculated, so it seems the question might be asking for something else or there is a typo.
If the question is about the interest earned quarterly compounded, the correct amount is approximately P132777.7.
**Final answer:** The amount after 9 years is approximately **P132777.7**.