SCENARIO 18-9
What are the factors that determine the acceleration time (in sec. )from 0 to 60 miles per hour of a car? Data on the following variables for 171 different vehicle models were collected:
Accel Time: Acceleration time in sec.
Cargo Vol: Cargo volume in cu.ft.
HP: Horsepower MPG: Miles per gallon
SUV: 1 if the vehicle model is an SUV with Coupe as the base when SUV and Sedan are both 0 Sedan: 1 if the vehicle model is a sedan with Coupe as the base when SUV and Sedan are both 0
The regression results using acceleration time as the dependent variable and the remaining variables as the independent variables are presented below.
The various residual plots are as shown below.

The coefficient of partial determination ( R 2 yj.(All variables except j ) )of each of the 5 predictors are, respectively,0.0380,0.4376,0.0248,0.0188,and 0.0312.
The coefficient of multiple determination for the regression model using each of the 5 variables X j as the dependent variable and all other X variables as independent variables ( R 2 j )are,respectively, 0.7461,0.5676,0.6764,0.8582,0.6632.
-Referring to Scenario 18-9,which of the following assumptions is most likely violated based on the normal probability plot?
A)Linearity.
B)Normality of errors.
C)Equal variance.
D)None.

Question

SCENARIO 18-9
What are the factors that determine the acceleration time (in sec. )from 0 to 60 miles per hour of a car? Data on the following variables for 171 different vehicle models were collected:
Accel Time: Acceleration time in sec.
Cargo Vol: Cargo volume in cu.ft.
HP: Horsepower MPG: Miles per gallon
SUV: 1 if the vehicle model is an SUV with Coupe as the base when SUV and Sedan are both 0 Sedan: 1 if the vehicle model is a sedan with Coupe as the base when SUV and Sedan are both 0
The regression results using acceleration time as the dependent variable and the remaining variables as the independent variables are presented below.
  The various residual plots are as shown below.  
   
    The coefficient of partial determination ( R 2 yj.(All variables except j ) )of each of the 5 predictors are, respectively,0.0380,0.4376,0.0248,0.0188,and 0.0312.
The coefficient of multiple determination for the regression model using each of the 5 variables X j as the dependent variable and all other X variables as independent variables ( R 2 j )are,respectively, 0.7461,0.5676,0.6764,0.8582,0.6632.
-Referring to Scenario 18-9,which of the following assumptions is most likely violated based on the normal probability plot?
A)Linearity. 
B)Normality of errors. 
C)Equal variance. 
D)None.

Quizplus · Accepted Answer

Based on the normal probability plot, the assumption of normality of errors is most likely violated. The plot shows that the residuals do not follow a straight line, indicating that they are not normally distributed. This violates the assumption of normality of errors in regression analysis.

SCENARIO 18-9 What Are the Factors That Determine the Acceleration Time (In