Ok all you Physics buffs... Try This!?

You are driving a 2350 kg car at a constant speed of 20.8 m/s along an icy, but straight and level road. While approaching a traffic light, it turns red. You slam on the breaks. Your wheels lock, the tires begin skidding, and the car slides to a halt in a distance of 70.9 m. What is the coefficient of sliding friction (μ) between your tires and the icy roadbed?