You plan to start saving for your sons college education. He will begin college when he turns 18 years old and will need $4,000 at that time and in each of the following three years. You will make a deposit at the end of this year in an account that pays 6% compounded annually as well as an identical deposit at the end of each year, with the last deposit occurring when he turns 18. If an annual deposit of $1,484 will allow you to reach your goal, how old is your son now?

Plz show how to use the calculator, and let me know the answer!

Thank you very much