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QMB 3200 Exam Test Study Questions and Answers (Verified Answers) 1.The variable selection procedure that identifies the best regression equa- tion, given a specified number of independent variables, is ANS best-subsets re- gression.
2.The mathematical equation that explains how the dependent variable y is related to several independent variables and has the form is called ANS a multiple regression model.
3.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 1 / 3
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ANS increased by $1 (holding advertisement constant), the sales are expected to decrease by $3,000.
4.If a categorical variable has k levels, then ANS k - 1 dummy variables are needed.
5.When constructing a confidence or a prediction interval to quantify the relationship between two quantitative variables, the appropriate degrees of freedom are ANS n-2 6.Influential observations always ANS 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.
7.The model developed from sample data that has the form is known as the 2 / 3
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ANS estimated regression equation.
8.When autocorrelation is present, which of the following assumptions is violated ANS The error terms are independent.
9.When we conduct significance tests for a multiple regression relationship, the F test will be used as the test for ANS overall significance.
10.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 statis- tic ANS The numerator degrees of freedom equals the number of predictors added to the model. The denominator degrees of freedom is n—p—1.