You would like to begin saving for you childrens college education. You have four kids, ages 4, 5, 7, and 15. Each child will begin college at 18 and attend a public university for four years. Tuition is currently $20,000 per year and is increasing at 4.5% per year. You can earn a 7% return on your investments. How much must you save at the end of each year if you would like to make the last payment during your youngest childs last year of college?