You are making a savings plan to pay for you child's college tuition. Assume your child was just born, and you will deposit $$5,500$ into a savings plan $($like RESP$)$ every year for ten years beginning today. That is$,$ your first deposit into your child's college savings plan account will be today, and the tenth and final deposit will be on the day your child turns nine. Your child will start a four$-$year college on the day they turn $18,$ and identical annual tuition payments of $X will be due on your child's $18$th$,19$th$,20$th$,$ and $21$st birthdays. What is the highest annual tuition payment $X that can be covered by funds from the savings plan? Use $7\mathrm{.}9\%$ as the annual discount rate. The answer is $43890.$ How to calculate this?