Please help

Advanced Math 66 Six years from now, when you tum 55, you are planning to retire. You want to set aside some money today so you can receive $2,500 at the end of every quarter for 15 years with the first withdrawal 3 months after you tum 55. The invested funds earn 9% compounded semi-annually. a. What amount must you invest today? b. How much interest will you earn during the 21 years