An air traffic controller is using radar to track the position of an airplane moving due east at a constant speed. The table below shows the position of the aircraft on her screen, relative to the left edge, and the time at which the aircraft was spotted. Position (cm) 0 0.70 1.40 2.10 3.50 Time (minutes) 0 0.25 0.50 0.75 1.25 If each centimeter on the screen represents 5 kilometers, what is the speed that the airplane is flying in kilometers per hour? kilometers per hour