Question 1201425
this is not usually done.
if you have monthly payments, the interest rate is usually compounded monthly.
in that case, the monthly interest rate would be 6.5 / 12 = .541666667%
if the interest rate is compounded annually, then the monthly interest rate would be equal to 1.065 ^ (1/12) = 1.005261694 - 1 = .005261694 * 100 = .5261694%.
this makes a difference in what the monthly payments would be.
with monthly compounding, the payments at the end of each month would be equal to 3406.44.
the total interest paid would be equal to 120 * 3406.44 - 300,000 = 108,772.8.
with annual compounding, the payments at the end of each month would be equal to   3378.12.
the total interest paid would be equal to 120 * 3378.12 - 300,000 = 105,374.4.