Problem 6-72 Calculating Interest Rates [LO4)] A financial planning service offers a college savings program. The plan calls for you to make six annual payments of $15,500 each, with the first payment occurring today, your child's 12th birthday. Beginning on your child's 18th birthday, the plan will provide $28,000 per year for four years. What return is this investment offering? (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) Return /0