Exam 14: Building Multiple Regression Models

Alan Bissell,a market analyst for City Sound Mart,is analyzing sales of heavy metal CD's.Alan's dependent variable is annual heavy metal CD sales (in $1,000,000's),and his independent variables are teenage population (in 1,000's)and type of sales district (0 = urban,1 = rural).Regression analysis of the data yielded the following tables: For two sales districts with the same number of teenagers one urban and one rural,Alan's model predicts ___.

If a qualitative variable has c categories,then only (c - 1)dummy variables must be included in the regression model.

If a data set contains k independent variables,the "all possible regression" search procedure will determine 2^k - 1 different models.

After a transformation of the y-variable values into log y,and performing a regression analysis produced the following tables: For x₁= 10,the predicted value of y is ___.

The following scatter plot indicates that ___.

Yvonne Yang,VP of Finance at Discrete Components,Inc.(DCI),wants a regression model which predicts the average collection period on credit sales.Her data set includes two qualitative variables: sales discount rates (0%,2%,4%,and 6%),and total assets of credit customers (small,medium,and large).The number of dummy variables needed for "total assets of credit customer" in Yvonne's regression model is ___.

The regression model y = $\beta$ ₀ + $\beta$ ₁ x₁ + $\beta$ ₂ x²₁ + $\varepsilon$ is called a quadratic model.

Abby Kratz,a market specialist at the market research firm of Saez,Sikes,and Spitz,is analyzing household budget data collected by her firm.Abby's dependent variable is monthly household expenditures on groceries (in $'s),and her independent variables are annual household income (in $1,000's)and household neighbourhood (0 = suburban,1 = rural).Regression analysis of the data yielded the following table: For a rural household with $70,000 annual income,Abby's model predicts monthly grocery expenditure of ___.

Alan Bissell,a market analyst for City Sound Mart,is analyzing sales of heavy metal CD's.Alan's dependent variable is annual heavy metal CD sales (in $1,000,000's),and his independent variables are teenage population (in 1,000's)and type of sales district (0 = urban,1 = rural).Regression analysis of the data yielded the following tables: For an urban sales district with 10,000 teenagers,Alan's model predicts annual sales of heavy metal CD sales of ___.

An appropriate method to identify multicollinearity in a regression model is to ___.

A multiple regression analysis produced the following tables: These results indicate that ___.

Qualitative data cannot be incorporated into linear regression models.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals that the first independent variable entered by the forward selection procedure will be ___.

An "all possible regressions" search of a data set containing 7 independent variables will produce ___ regressions.

A multiple regression analysis produced the following tables: Using $\alpha$ = 0.05 to test the null hypothesis H₀: $\beta$ ₁ = $\beta$ ₂ = 0,the critical F value is ___.

Examine the role of indicator,or dummy,variables as predictors or independent variables in multiple regression analysis.

Which of the following iterative search procedures for model building in a multiple regression analysis re-evaluates the contribution of variables previously included in the model after entering a new independent variable?

A useful tool in improving the regression model fit is recoding data.

A multiple regression analysis produced the following tables: For x₁= 10,the predicted value of y is ___.

If a qualitative variable has "c" categories,how many dummy variables must be created and used in the regression analysis?