UCF QMB 3200 FINAL EXAM
Which of the following is not an iterative variable selection
procedure? - ANSWERS-Best-subsets regression
Multicollinearity can cause problems if the absolute value of the
sample correlation coefficient exceeds - ANSWERS-0.7 for any two
of the independent variables
The variable selection procedure that identifies the best regression
equation, given a specified number of independent variables, is -
ANSWERS-Best-subsets regression.
The regression model y=B0+B1x1+B2x1^2+e is a - ANSWERS-
Second-order model with one predictor variable.
In order to use the output from a multiple regression model to perform
the ANOVA test on the difference among the means of four
populations, how many dummy variables do we need to use to
indicate treatments? - ANSWERS-Three
When dealing with the problem of nonconstant variance, we can
apply the reciprocal transformation, which means that we use -
ANSWERS-1/y as the dependent variable instead of y.
,Correlation in the errors that arises when the error terms at successive
points in time are related is called - ANSWERS-autocorrelation.
Write a multiple regression equation that can be used to analyze the
data for a two-factorial design with two levels for factor A and four
levels for factor B. - ANSWERS-The longest one that ends with 1 and
4
The range of the Durbin-Watson statistic is - ANSWERS-0 to 4.
The Durbin-Watson test is generally inconclusive for - ANSWERS-
Smaller sample sizes
Using the two-factorial design, write the form of the multiple
regression equation that would give the expected value for level 1 of
factor A and level 3 of factor B. - ANSWERS-E(y)=B0+b3
Suppose a high correlation existed between variables x 1 and x 2 . If
variable x 1 was used as an independent variable, then variable x 2 -
ANSWERS-would not add much more explanatory power to the
current model.
In best-subsets regression, Minitab can be used to provide output that
identifies the two best one-variable estimated regression equations,
the two best two-variable estimated regression equations, the two best
three-variable estimated regression equations, and so on. What
criterion is used in determining which estimated regression equations
are best? - ANSWERS-R^2
,What value of Durbin-Watson statistic indicates that no
autocorrelation is present? - ANSWERS-Two.
When determining the best estimated regression equation to model a
set of data, the procedure that begins each step by determining
whether any of the variables already in the model should be removed
is called - ANSWERS-Stepwise regression
A model in the form of , where each independent variable zj (for j = 1,
2,..., p) is a function of x1, x2,..., xk, is known as the: - ANSWERS-
general linear model.
If the value of y in time period t is related to its value in time period t
- 1, we say that - ANSWERS-first-order autocorrelation is present.
The effect of two independent variables acting together is called -
ANSWERS-Interaction.
Which of the following options guarantees that the best model for a
given number of variables will be found? - ANSWERS-Best-subsets
regression
How many independent variables does the forward selection process
start with? - ANSWERS-Zero
, Which of the following statements about the backward elimination
procedure is false? - ANSWERS-It begins with zero independent
variables.
When determining the best estimated regression equation to model a
set of data, the procedure that allows an independent variable to enter
the model at one step, be removed at a subsequent step, and then enter
the model at a later step is - ANSWERS-stepwise regression.
The parameters of nonlinear models have exponents - ANSWERS-
other than one.
In multiple regression analysis, the general linear model: -
ANSWERS-can be used to accommodate curvilinear relationships
between the independent variables and the dependent variable.
Suppose sales data for the first quarter had a seasonal index of .80.
Which of the following statements correctly interprets this figure? -
ANSWERS-The sales average is 20% below the trend estimate.
The time series model that is appropriate in situations where the
seasonal fluctuations do not depend upon the level of the time series
is - ANSWERS-Additive model.
The average of the sum of squared forecast errors is called -
ANSWERS-mean squared error.
Which of the following is not an iterative variable selection
procedure? - ANSWERS-Best-subsets regression
Multicollinearity can cause problems if the absolute value of the
sample correlation coefficient exceeds - ANSWERS-0.7 for any two
of the independent variables
The variable selection procedure that identifies the best regression
equation, given a specified number of independent variables, is -
ANSWERS-Best-subsets regression.
The regression model y=B0+B1x1+B2x1^2+e is a - ANSWERS-
Second-order model with one predictor variable.
In order to use the output from a multiple regression model to perform
the ANOVA test on the difference among the means of four
populations, how many dummy variables do we need to use to
indicate treatments? - ANSWERS-Three
When dealing with the problem of nonconstant variance, we can
apply the reciprocal transformation, which means that we use -
ANSWERS-1/y as the dependent variable instead of y.
,Correlation in the errors that arises when the error terms at successive
points in time are related is called - ANSWERS-autocorrelation.
Write a multiple regression equation that can be used to analyze the
data for a two-factorial design with two levels for factor A and four
levels for factor B. - ANSWERS-The longest one that ends with 1 and
4
The range of the Durbin-Watson statistic is - ANSWERS-0 to 4.
The Durbin-Watson test is generally inconclusive for - ANSWERS-
Smaller sample sizes
Using the two-factorial design, write the form of the multiple
regression equation that would give the expected value for level 1 of
factor A and level 3 of factor B. - ANSWERS-E(y)=B0+b3
Suppose a high correlation existed between variables x 1 and x 2 . If
variable x 1 was used as an independent variable, then variable x 2 -
ANSWERS-would not add much more explanatory power to the
current model.
In best-subsets regression, Minitab can be used to provide output that
identifies the two best one-variable estimated regression equations,
the two best two-variable estimated regression equations, the two best
three-variable estimated regression equations, and so on. What
criterion is used in determining which estimated regression equations
are best? - ANSWERS-R^2
,What value of Durbin-Watson statistic indicates that no
autocorrelation is present? - ANSWERS-Two.
When determining the best estimated regression equation to model a
set of data, the procedure that begins each step by determining
whether any of the variables already in the model should be removed
is called - ANSWERS-Stepwise regression
A model in the form of , where each independent variable zj (for j = 1,
2,..., p) is a function of x1, x2,..., xk, is known as the: - ANSWERS-
general linear model.
If the value of y in time period t is related to its value in time period t
- 1, we say that - ANSWERS-first-order autocorrelation is present.
The effect of two independent variables acting together is called -
ANSWERS-Interaction.
Which of the following options guarantees that the best model for a
given number of variables will be found? - ANSWERS-Best-subsets
regression
How many independent variables does the forward selection process
start with? - ANSWERS-Zero
, Which of the following statements about the backward elimination
procedure is false? - ANSWERS-It begins with zero independent
variables.
When determining the best estimated regression equation to model a
set of data, the procedure that allows an independent variable to enter
the model at one step, be removed at a subsequent step, and then enter
the model at a later step is - ANSWERS-stepwise regression.
The parameters of nonlinear models have exponents - ANSWERS-
other than one.
In multiple regression analysis, the general linear model: -
ANSWERS-can be used to accommodate curvilinear relationships
between the independent variables and the dependent variable.
Suppose sales data for the first quarter had a seasonal index of .80.
Which of the following statements correctly interprets this figure? -
ANSWERS-The sales average is 20% below the trend estimate.
The time series model that is appropriate in situations where the
seasonal fluctuations do not depend upon the level of the time series
is - ANSWERS-Additive model.
The average of the sum of squared forecast errors is called -
ANSWERS-mean squared error.
