A homeowner is considering adding a sunspace to his home. The project is completed during 4 years and requires \($20,000\) to be spent the first year, \($15,000\) the second year,(\($10,000\)\) the third year, and \($5,000\) the fourth year. Determine how much money the homeowner needs to set aside to pay for the sunspace addition project:

(a) If the interest rate is 4% per year, compounded annually.

(b) If the interest rate is 8% per year, compounded annually.