Biyu borrows $L for 9 years at a nominal interest rate j1 (4) = 8.310%. The loan is to be repaid in level annual installments. The principal repayment portion of the second payment is $4643.40. a) (6 marks) Prove that for any level pay loan with n payments of amount $K, and effective interest rate per period i, PR= K * vn-t+1 (where v = 1/(1 + i)) b) (2 marks) What is $L? (Hint: you can use the result of part a) even if you can't prove it.) c) (2 marks) What is the outstanding balance on the loan just after the 6th payment has been made? d) (2 marks) What is the total amount of interest Biyu pays over the lifetime of the loan