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) 0.70 1.40 2.10 3.50 Time (minutes) 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