A transit company operates commuter trains to help people get to the city each day Each train travels on a straight route to and from the farthest station stopping at other stations along the route The graph shows the distance y miles the train is from the station after x minutes Commuter Train Distance Distance from the Station miles 25 20 y 0 10 20 30 40 50 60 70 80 Time minutes Formula Sheet Calculator Referen Type your answer in the box You may use numbers a decimal point and or a negative sign in your answer Based on the graph what was the average speed in miles per minute of the trai during the interval of 30 to 40 minutes