Your university advertises that next year's "discounted" tuition of $8,000 can be paid in full by July 1. The other option is to pay the first semester's tuition of $4,200 by July 1, with the remaining $4,200 due on January 1. Assuming you and/or your parents have $8,000 available for the full year's tuition, which tuition plan is more economical if you (or your parents) can earn 6% annually on a six-month CD?