(Annuity interest rate) Your folks just called and would like some advice from you. An insurance agent just called them and offered them the opportunity to purchase an annuity for $29,355.45 that will pay them $3,500 per year for 20 years. They don't have the slightest idea what return they would be making on their investment of $29,355.45. What rate of return would they be earning? The annual rate of return your folks would be earning on their investment is 10%. (Round to two decimal places.)