Question: (Solving for r in an annuity) 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 $21,074.25 that will pay them $3,000 per year for 20 years, but they don't have the slightest idea what return they will be making on their investment of $21,074.25. What rate of return will they be earning?