348 Problem 2: (5 points) Table 1 presents the highway gasoline mileage performance and engine displacement for DaimlerChrysler vehicles for model year 2005 (U.S. Environmental Protection Agency) Table 1: Gasoline Mileage Data Engine MPG Carline Displacement in the way! 300C/SRT-8 215 30.8 CARAVAN ZWD 201 32.5 CROSSFIRE 196 35.4 ROADSTER DAKOTA PICKUP 2WD 226 DAKOTA PICKUP 4WD 226 24.4 DURANGO 2WD 348 GRAND 226 28,3 CHEROKEE 2WD GRAND 24.2 CHEROKEE 4WD LIBERTY 148 32.8 CHEROKEE 2WD LIBERTY/ 226 CHEROKEE 4WD NEONSRT-USX 20 122 41.3 PACIFICA 2WD 215 30.0 PACIFICA AWD 215 282 PT CRUISER 145 341 RAM 1500 PICKUP 500 18.7 2WD RAM 1500 PICKUP 348 203 4WD SEBRING 4-DR 165 35.1 STRATUS 4-DR 148 379 TOWN & COUNTRY 148 33.8 2WD VIPER CONVERTIBLE 500 25.9 WRANGLER/TJ 4WD 148 26.4 a) Fit a simple lincar model relating highway miles per gallon () to engine displacement (r) in cubic inches using least squares. b) Find an estimate of the mean highway gasoline mileage performance for a car with 150 cubic inches engine displacement. c) Obtain the fitted value of y and the corresponding residual for a car, the Neon, with an engine displacement of 122 cubic inches. Problem 3: (5 points) An article in the Journal of Sound and Vibration (1991, Vol. 151, pp. 383-394) described a study investigating the relationship between noise exposure and hypertension. The following data are representative of those reported in the article. 1 0 1 2. 5 1 4 6 2 3 x 60 63 65 70 70 70 80 90 80 80 y 5 4 6 8 4 5 7 9 7 6 89 90 90 90 90 94 100 100 100 x 85 a) Draw a scatter diagram of y(blood pressure rise in millimeters of mercury) versus (sound pressure level in decibels). Does a simple linear regression model seem reasonable in this situation? b) Fit the simple linear regression model using least squares. Find an estimate of o? c) Find the predicted mean rise in blood pressure level associated with a sound pressure level of 94 decibels