arren has a loan with an effective interest rate of 5 percent per annum. He makes payments at the end of each year for 10 years. The first payment is 200, and each subsequent payment increases by 10 per year. Calculate the interest portion in the fifth payment.

interest portion of fifth payment = $66.89 ≈ $67

Explanation:

effective interest rate = 5% yearly

first payment = $200

second payment = $210

third payment = $220

fourth payment = $230

fifth payment = $240

sixth payment = $250

seventh payment = $260

eighth payment = $270

ninth payment = $280

tenth = $290

using a financial calculator, I determined the present value (principal) of the loan = $1,860.87

then I prepared an amortization schedule:

interest portion of fifth payment = $66.89 ≈ $67