A study on driving speed (miles per hour) and fuel efficiency (miles per gallon) for midsize automobiles resulted in the following data: Click on the datafile logo to reference the data. Driving Speed 30 50 40 55 30 25 60 25 50 55 Fuel Efficiency 28 25 25 23 30 32 21 35 26 25 a. Which of the following is a scatter diagram with driving speed on the horizontal axis and fuel efficiency on the vertical axis? 1.