Question 13.56

displacement

56. Engine Displacement and Gas Mileage. The table provides the engine displacement (size, in liters) and the city MPG (miles per gallon) gas mileage of a random sample of 12 vehicles.

  1. Construct a 95% confidence interval for the slope of the regression line, for the regression of city MPG on engine displacement.
  2. Using your confidence interval, conclude whether a linear relationship exists between city MPG and engine displacement, with level of significance .
Vehicle Engine
displacement		 City MPG
GMC Yukon Denali 6.2 13
Ford E350 Wagon 5.4 11
BMW 435i Coupe 3.0 20
Land Rover Range Rover 5.0 13
Infiniti Q50a 3.7 19
Dodge Journey 3.6 17
Jaguar XF 5.0 15
Dodge Challenger 6.4 14
Toyota Highlander Hybrid 3.5 28
Mercedes-Benz S 550 4.7 17
Ford Fiesta 1.6 29
Hyundai Elantra 2.0 24