60mph + skidmarks on a vehicle?

Here is my question for physics. A vehicle traveling at 60 MPH started skidding along the pavement then on the median of a freeway. The skid marks on the pavement are 75ft long and the skidmarks on the median are 62 ft long. Calc the velocity of the car at the point of impact with a median barrier at the end of the skidding distance. ume a grade of -2.2% and friction coefficients of .45 and .25 in the pacement and median, respectively. Help please.