Exam 14: Building Multiple Regression Models

A local parent group was concerned with the increasing school cost for families with school aged children.The parent group was interested in understanding the relationship between the The academic grade level for the child and the total costs spent per child per academic year.They Performed a multiple regression analysis using total cost as the dependent variable and academic Year (x₁)as the independent variables.The multiple regression analysis produced the following Tables. The regression equation for this analysis is ____________.

If the variance inflation factor is bigger than 10,the regression analysis might suffer from the problem of multicollinearity.

Multiple linear regression models can handle certain nonlinear relationships by ________.

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 weekly household expenditures on groceries (in $'s),and her independent variables are annual household income (in $1,000's)and household neighborhood (0 = suburban,1 = rural). Regression analysis of the data yielded the following table. For a rural household with $90,000 annual income,Abby's model predicts weekly grocery expenditure of ________________.

The following scatter plot indicates that _________.

A multiple regression analysis produced the following tables. Using $\alpha$ = 0.10 to test the null hypothesis H₀: $\beta$ ₂ = 0,the critical t value is ____.

Inspection of the following table of correlation coefficients for variables in a multiple regression analysis reveals potential multicollinearity with variables ___________.

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 "sales discount rate" in Yvonne's regression model is ________.

If a qualitative variable has c categories,then c dummy variables must be included in the regression model,one for each category.

If two or more independent variables are highly correlated,the regression analysis might suffer from the problem of singular collinearity.

Large correlations between two or more independent variables in a multiple regression model could result in the problem of ________.

If the effect of an independent variable (e.g.,square footage)on a dependent variable (e.g.,price)is affected by different ranges of values for a second independent variable (e.g.,age ),the two independent variables are said to interact.

The following scatter plot indicates that _________.

If a square-transformation is applied to a series of positive numbers,all greater than 1,the numerical values of the numbers in the transformed series will be smaller than the corresponding numbers in the original series.

The regression model y = $\beta$ ₀ + $\beta$ ₁ x₁ + $\beta$ ₂ x₂ + $\beta$ ₃ x₃ + $\varepsilon$ is a third order model.

A local parent group was concerned with the increasing school cost for families with school aged children.The parent group was interested in understanding the relationship between the The academic grade level for the child and the total costs spent per child per academic year.They Performed a multiple regression analysis using total cost as the dependent variable and academic Year (x₁)as the independent variables.The multiple regression analysis produced the following Tables. Using $\alpha$ = 0.05 to test the null hypothesis H₀: $\beta$ ₁ = 0,the critical t value is ____.

If a coefficient of determination for a given model is 0.85,then its variance inflation factor is ______.

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 ________.

If each pair of independent variables is weakly correlated,there is no problem of multicollinearity.

Alan Bissell,a market analyst for City Sound Online Mart,is analyzing sales from heavy metal song downloads.Alan's dependent variable is annual heavy metal song download sales (in $1,000,000's),and his independent variables are website visitors (in 1,000's)and type of download format requested (0 = MP3,1 = other).Regression analysis of the data yielded the following tables. For an MP3 sales with 10,000 website visitors,Alan's model predicts annual sales of heavy metal dong downloads of ________________.