Question 4.182

Fuel Economy. Refer to the following table of fuel economy data for a sample of 10 vehicles for Exercises 80–84. The predictor variable is $x = engine size$ , expressed in liters; the response variable is $y = combined (city/highway) gas mileage$ , expressed in miles per gallon (mpg).

Vehicle	$x = engine size (liters)$	$y = combined mpg$
Mini Cooper	1.6	31
Ford Focus	2.0	28
Toyota Camry	2.5	26
Honda Accord	2.4	26
Subaru Forester	2.5	23
Toyota Highlander	2.7	22
Ford Taurus	3.5	20
Chevrolet Equinox	3.0	19
Dodge Nitro	4.0	17
Cadillac limousine	4.6	14

Question 4.182

enginempg

84. Making Predictions. Answer the following:

Note that the Chevrolet Equinox has an engine size of 3 liters. Predict the combined mpg for a vehicle with an engine size of 3 liters.
Is your prediction error positive or negative? Thus, does the data value lie above or below the regression line? What does this mean?