Accident ysis Question- Physics Problem?

You have been called to testify as an expert witness in a trial involving an automobile accident. The speed limit on the highway where the accident took place was 40mph. The driver of the car slammed on the brakes, and left skid marks to be 219ft 9in (the coefficent of kinetic fric wheels and pavement is .40). How fast was this car traveling (to the nearest # of mph) just before the driver hit his brakes? Was he guilty of speeding?