Loan Interest
1. **State the problem:** We want to calculate the total interest paid on a loan of $169255 with an annual interest rate of 4%, paid monthly over 30 years.
2. **Identify variables:**
- Principal ($P$) = 169255
- Annual interest rate ($r$) = 4% = 0.04
- Number of years ($t$) = 30
- Number of payments per year ($n$) = 12
3. **Calculate monthly interest rate:**
$$ i = \frac{r}{n} = \frac{0.04}{12} = 0.0033333333 $$
4. **Calculate total number of payments:**
$$ N = n \times t = 12 \times 30 = 360 $$
5. **Calculate monthly payment using the formula for an amortizing loan:**
$$ M = P \times \frac{i (1+i)^N}{(1+i)^N -1} $$
Substituting values:
$$ M = 169255 \times \frac{0.0033333 (1+0.0033333)^{360}}{(1+0.0033333)^{360} -1} $$
6. **Compute $(1+i)^{360}$:**
$$ (1.0033333)^{360} \approx 3.2434 $$
7. **Calculate numerator:**
$$ 0.0033333 \times 3.2434 = 0.0108113 $$
8. **Calculate denominator:**
$$ 3.2434 -1 = 2.2434 $$
9. **Calculate monthly payment:**
$$ M = 169255 \times \frac{0.0108113}{2.2434} = 169255 \times 0.004817 = 815.18 $$
10. **Calculate total amount paid over 30 years:**
$$ \text{Total paid} = M \times N = 815.18 \times 360 = 293464.80 $$
11. **Calculate total interest paid:**
$$ \text{Interest} = \text{Total paid} - P = 293464.80 - 169255 = 124209.80 $$
12. **Round to nearest hundredth:** Interest is already to two decimal places.
**Final answer:** The total interest paid is $124209.80$.