During four years of college, Nolan MacGregor's student loans are $4,000, $3,500, $4,400, and $5,000 for freshman year through senior year, respectively. Each loan amount gathers interest of 2%, compounded quarterly, while Nolan is in school and 3%, compounded quarterly, during a 6-month grace period after graduation.

fuarterly, during a 6-month grace period after graduation. answer to the nearest cent.) $ (c) If Nolan decides to pay an additional $90 per payment, how many payments will amortize the debt? (Round your answer to two decimal places.) payments What amount (in dollars) should be added to the last payment to pay the loan in full? (Round your answer to the nearest cent.) $ (d) How much will Nolan save (in dollars) by paying the extra $90 with each payment? (Round your answer to the nearest cent.)