An engineer collects the following data showing the speed s of a Toyota Camry and its average miles per gallon,M.

Speed, s …………….............…………. Miles per Gallon, M

30……………………………………….. 18

35 ……………………………………….. 20

40 ……………………………………….. 23

40 ……………………………………….. 25

  45 ………………………………………. 25

50 ……………………………………….. 28

55 ……………………………………….. 30

60 ……………………………………….. 29

65 ……………………………………….. 26

65 ……………………………………….. 25

70 ……………………………………….. 25

(a) Using a graphing utility, draw a scatter diagram of the data treating speed as the independent variable.What type of relation appears to exist between speed and miles per gallon?

(b) Based on your response to part (a), find either a linear or quadratic model that describes the relation between speed and miles per gallon.

(c) Use your model to predict the miles per gallon for a Camry that is traveling 63 miles per hour.