P5 = 1800, I5=i*OLB4, add P5 and I5 to get R5

To find the 15th payment, consider OLB6. It is L-(sum of the first 6 principal payments), find this numbe r.

Set this number equal to the PV at t=6 of all future payments, i.e. we take the prospective approach. Solve

for the last payment this way.

(4) Eliza takes out a $36,000 loan at an annual effective interest rate of 6%. It is agreed that at the end of each of the first six years she will pay $1,800 in principal, along with the interest due, and that at the end of each of the next eight years she will make level payments of $2,500. Eliza will make one final payment at the end of fifteen years to exactly complete her loan obligation. Calculate the amount of Eliza's fifth payment, the amount of her tenth pay- ment, and the amount of her fifteenth payment