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 $$27,259\mathrm{.}57$ that will pay them $$4,000$ per year for $20$ years. They don't have the slightest idea what return they would be making on their investment of $$27,259\mathrm{.}57.$ What rate of return would they be earning?