Bill O'Brien would like to take his wife, Mary, on a trip four years from now to Europe to celebrate their 40th anniversary. He has just received a $18737 inheritance from an uncle and intends to invest it for the trip. Bill estimates the trip will cost $25056 and he believes he can earn reasonable interest, compounded annually, on his investment. What interest rate, compounded annually, must Bill earn to accumulate enough to pay for the trip? Answer in percent to two decimal places ( 0.00 %).