Jimmy buys a house for $232,000. He makes a down payment of $20,000 and finances the balance. How much are his monthly payments if the current rate is 4.6% and it is a fifteen year loan?

1 answer

To calculate Jimmy's monthly mortgage payment, we can use the formula for a fixed-rate mortgage, which is given by:

\[ M = P \frac{r(1 + r)^n}{(1 + r)^n - 1} \]

Where:

  • \( M \) = monthly payment
  • \( P \) = principal loan amount (the amount financed)
  • \( r \) = monthly interest rate (annual rate / 12 months)
  • \( n \) = number of payments (loan term in months)

Step 1: Determine the Principal Loan Amount

Jimmy's house costs $232,000, and he makes a down payment of $20,000. Therefore, the principal loan amount (\( P \)) is:

\[ P = 232,000 - 20,000 = 212,000 \]

Step 2: Calculate the Monthly Interest Rate

The annual interest rate is 4.6%, so we need to convert this to a monthly rate:

\[ r = \frac{4.6%}{100} \div 12 = \frac{0.046}{12} \approx 0.00383333 \]

Step 3: Determine the Number of Payments

For a 15-year loan, the total number of payments (\( n \)) is:

\[ n = 15 \times 12 = 180 \text{ months} \]

Step 4: Calculate the Monthly Payment

Now we can substitute these values into the mortgage payment formula:

\[ M = 212,000 \frac{0.00383333(1 + 0.00383333)^{180}}{(1 + 0.00383333)^{180} - 1} \]

First, we calculate \( (1 + r)^{n} \):

\[ (1 + 0.00383333)^{180} \approx 1.898322 \]

Now, plug that back into the formula:

\[ M = 212,000 \frac{0.00383333 \times 1.898322}{1.898322 - 1} \]

Calculating the numerator and denominator:

  • Numerator: \[ 0.00383333 \times 1.898322 \approx 0.007267 \]

  • Denominator: \[ 1.898322 - 1 \approx 0.898322 \]

So now,

\[ M = 212,000 \frac{0.007267}{0.898322} \approx 212,000 \times 0.008078 \] \[ M \approx 1717.53 \]

Final Result

Jimmy's estimated monthly mortgage payment is approximately $1,717.53.