Please help, connect says I am incorrect...

A financial planning service offers a college savings program. The plan calls for you to make six annual payments of $13,500 each, with the first payment occurring today, your childs 12th birthday. Beginning on your childs 18th birthday, the plan will provide $27,000 per year for four years.

What return is this investment offering? ________%

My work: Need to round to 2 decimal places:

Amount invested annually 13500 will be = 13500 * future value annuity factor 5 years + 1 = 13500*FVIFA 6,r% = 27000/Present value Interest annuity factor 4,r% What is the investment offering _________%

13500+ 13500*(1+r)^1 +......+13500*(1+r)^5= 27000/(1+r)^1 + .... +27000/(1+r)^4????