A metallurgical engineer decides to set aside money for his newborn daughter's college education. He estimates that her needs will be $20,000 on her l7th, 18th, 19th, and 20th birthdays. If he plans to make uniform deposits starting 3 years from now and continue through year 16, what shou ld be the size of each deposit, if the account earns interest at a rate of 8% per year?