As your bus rounds a flat curve at constant speed, a package with mass 0.900 , suspended from the luggage compartment of the bus by a string 46.0 long, is found to hang at rest relative to the bus, with the string making an angle of 27.0with the vertical. In this position, the package is 40.0 from the center of curvature of the curve. What is the speed of the bus?

I've been using the equation arad=v^2/r and put the radial acceleration in as tan(27)*(9.8*.9kg) which should be the force in the x direction, and then r as 40m and I get velocity as 13.4 m/s and the system says that its very close and ive made a rounding error possible, I then tried 13.5, 13.4, 13.2 and none of these worked and I have one shot left. Please help!!