Mortgage Calculation
1. **State the problem:** Calculate various mortgage-related amounts for a home priced at 237000 with a 20% down payment, three points at closing, and a 30-year fixed-rate mortgage at 7% interest.
2. **Find the required down payment:**
The down payment is 20% of the home price.
$$\text{Down payment} = 0.20 \times 237000 = 47400$$
3. **Find the amount of the mortgage:**
Mortgage amount is the home price minus the down payment.
$$\text{Mortgage} = 237000 - 47400 = 189600$$
4. **Calculate the cost of three points at closing:**
Points are fees based on the mortgage amount. One point = 1% of mortgage.
$$\text{Points cost} = 3\% \times 189600 = 0.03 \times 189600 = 5688$$
5. **Find the monthly payment (PMT):**
Use the formula for monthly mortgage payment:
$$PMT = P \times \frac{r(1+r)^n}{(1+r)^n - 1}$$
where
$P = 189600$ (loan amount),
$r = \frac{7\%}{12} = \frac{0.07}{12} \approx 0.0058333$ (monthly interest rate),
$n = 30 \times 12 = 360$ (total payments).
Calculate:
$$PMT = 189600 \times \frac{0.0058333(1+0.0058333)^{360}}{(1+0.0058333)^{360} - 1}$$
First compute $(1+0.0058333)^{360} \approx 10.677$.
Then:
$$PMT = 189600 \times \frac{0.0058333 \times 10.677}{10.677 - 1} = 189600 \times \frac{0.0623}{9.677} = 189600 \times 0.00644 = 1221$$
Rounded to nearest dollar, monthly payment is $1221$.
**Final answers:**
- Down payment: 47400
- Mortgage amount: 189600
- Points cost: 5688
- Monthly payment: 1221