Explanation:
For calculating the monthly cost of the loan, you generally need to use the monthly interest payment, which can be derived from the annual interest rate.
Monthly interest rate is calculated by dividing the annual loan costs from 12 (the number of months in one year) and assumption that the loan is compounded monthly.
This is, if the annual interest rate is 7.3%, then the monthly Interest Rate will be:
r = 0.073 / 12 = 0.0060833 (rounded to 7 decimal places) .
When calculating the monthly loan payment, you need to use this value of R in your schedule for calculating the monthly loan payment.