a. To calculate the monthly payment from United Bank, we need to use the formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
where M is the monthly payment, P is the principal amount, i is the monthly interest rate, and n is the number of monthly payments.
For United Bank, the principal amount is $120,000, the monthly interest rate is 6.2% / 12 = 0.00517, and the number of monthly payments is 15 years x 12 months/year = 180 months.
Plugging these values into the formula, we get:
M = 120000 [ 0.00517(1 + 0.00517)^180 ] / [ (1 + 0.00517)^180 – 1] = $1,011.25
Therefore, the monthly payment from United Bank is $1,011.25.
b. To calculate the total interest from United Bank, we can multiply the monthly payment by the number of payments and subtract the principal amount. The total interest is:
Total interest = M x n - P = $1,011.25 x 180 - $120,000 = $82,025
Therefore, the total interest from United Bank is $82,025.
c. To calculate the monthly payment from Capitol Bank, we can use the same formula as above. For Capitol Bank, the principal amount is $120,000, the monthly interest rate is 6.5% / 12 = 0.00542, and the number of monthly payments is 25 years x 12 months/year = 300 months.
Plugging these values into the formula, we get:
M = 120000 [ 0.00542(1 + 0.00542)^300 ] / [ (1 + 0.00542)^300 – 1] = $782.49
Therefore, the monthly payment from Capitol Bank is $782.49.
d. To calculate the total interest from Capitol Bank, we can use the same method as above. The total interest is:
Total interest = M x n - P = $782.49 x 300 - $120,000 = $154,747
Therefore, the total interest from Capitol Bank is $154,747.
e. United Bank has the lower total interest, by $72,722.
f. The difference in the monthly payments is $1,011.25