QMB 3200 Exam 3 |Complete Questions with 100% Correct Answers
The variable selection procedure that identifies the best regression equation, given a specified number
of independent variables, is:
best-subsets regression.
The mathematical equation that explains how the dependent variable y is related to several
independent variables and has the form is called:
a multiple regression model.
A regression model between sales ( in $1,000) and unit price (x1 in dollars) and television advertisement
(x2 in dollars) resulted in the following function: . The coefficient of the unit price indicates that if the
unit price is:
increased by $1 (holding advertisement constant), the sales are expected to decrease by $3,000.
If a categorical variable has k levels, then:
k - 1 dummy variables are needed.
When constructing a confidence or a prediction interval to quantify the relationship between two
quantitative variables, the appropriate degrees of freedom are:
n-2
Influential observations always:
None of the above are correct. They can increase or decrease the value of the slope, correlation, and y-
intercept depending on where they fall in relation to the rest of the points in the data set.
The model developed from sample data that has the form is known as the:
estimated regression equation.
When autocorrelation is present, which of the following assumptions is violated?
The error terms are independent.
high leverage points
The mathematical equation relating the independent variable to the expected value of the dependent
variable, , is known as the:
Dummy variables must always have:
When we conduct significance tests for a multiple regression relationship, the F test will be used as the
test for:
overall significance.
, When carrying out an F test to determine if the addition of extra predictor variables results in a
significant reduction in the error sum of squares, what are the degrees of freedom of the numerator and
denominator of the F statistic?
The numerator degrees of freedom equals the number of predictors added to the model. The
denominator degrees of freedom is n—p—1.
How many independent variables does the forward selection process start with?
Zero
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?
R^2
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?
Three
The effect of two independent variables acting together is called:
interaction.
The tests of significance in regression analysis are based on assumptions about the error term ɛ. One
such assumption is that the error term follows ɛ a(n) _____ distribution for all values of x.
normal
In multiple regression analysis, the general linear model:
can be used to accommodate curvilinear relationships between the independent variables and the
dependent variable.
An observation that has a strong influence or effect on the regression results is called a(n):
influential observation.
In a regression analysis, an outlier will always increase:
the value of the correlation.
In multiple regression analysis:
there can be several independent variables, but only one dependent variable.
The value of the coefficient of correlation (r):
can be equal to the value of the coefficient of determination (r^2).
The variable selection procedure that identifies the best regression equation, given a specified number
of independent variables, is:
best-subsets regression.
The mathematical equation that explains how the dependent variable y is related to several
independent variables and has the form is called:
a multiple regression model.
A regression model between sales ( in $1,000) and unit price (x1 in dollars) and television advertisement
(x2 in dollars) resulted in the following function: . The coefficient of the unit price indicates that if the
unit price is:
increased by $1 (holding advertisement constant), the sales are expected to decrease by $3,000.
If a categorical variable has k levels, then:
k - 1 dummy variables are needed.
When constructing a confidence or a prediction interval to quantify the relationship between two
quantitative variables, the appropriate degrees of freedom are:
n-2
Influential observations always:
None of the above are correct. They can increase or decrease the value of the slope, correlation, and y-
intercept depending on where they fall in relation to the rest of the points in the data set.
The model developed from sample data that has the form is known as the:
estimated regression equation.
When autocorrelation is present, which of the following assumptions is violated?
The error terms are independent.
high leverage points
The mathematical equation relating the independent variable to the expected value of the dependent
variable, , is known as the:
Dummy variables must always have:
When we conduct significance tests for a multiple regression relationship, the F test will be used as the
test for:
overall significance.
, When carrying out an F test to determine if the addition of extra predictor variables results in a
significant reduction in the error sum of squares, what are the degrees of freedom of the numerator and
denominator of the F statistic?
The numerator degrees of freedom equals the number of predictors added to the model. The
denominator degrees of freedom is n—p—1.
How many independent variables does the forward selection process start with?
Zero
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?
R^2
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?
Three
The effect of two independent variables acting together is called:
interaction.
The tests of significance in regression analysis are based on assumptions about the error term ɛ. One
such assumption is that the error term follows ɛ a(n) _____ distribution for all values of x.
normal
In multiple regression analysis, the general linear model:
can be used to accommodate curvilinear relationships between the independent variables and the
dependent variable.
An observation that has a strong influence or effect on the regression results is called a(n):
influential observation.
In a regression analysis, an outlier will always increase:
the value of the correlation.
In multiple regression analysis:
there can be several independent variables, but only one dependent variable.
The value of the coefficient of correlation (r):
can be equal to the value of the coefficient of determination (r^2).
