Solve without using excel, we're using the prospective/ retrospective methods. A 30 year $100, 000 loan is made with effective annual interest i = 9% for the first 10 years and i = 7% for the next 20 years. The loan is paid off with constant yearly payments K beginning one year after the loan is made. Find K, and find the OB10 and OB25. Lastly, fill out the amortization table for 3 years.