Stacey takes a textbook to a pawnshop to borrow some money and is given $30.00. Stacey must pay back the $30.00 in addition to a $11.50 fee in 3 months. What simple interest rate is she being charged? Round to the nearest tenth of a percent and don't forget to include a percent sign, %, in your answer. Stacey is being charged a simple interest rate of _______________