Exam 15: Multiple Regression and Model Building

___________ is an iterative variable selection procedure that allows an independent variable to be added to a multiple regression model in one iteration and deleted during the next iteration.

Consider the following partial computer output for a multiple regression model.

Consider the following partial computer output for a multiple regression model.

Below is a partial multiple regression computer output.

The _________ regression method is used when the response variable is a qualitative or a categorical variable.

If a regression model with k independent variables has a C statistic less than _______,then the model is considered to be desirable.

For the same point estimate of the dependent variable and the same level of significance,the confidence interval is always wider than the corresponding prediction interval.

The manufacturer of a light fixture believes that the dollars spent on advertising,the price of the fixture,and the number of retail stores selling the fixture in a particular month influence the light fixture sales.The manufacturer randomly selects 10 months and collects the following data:

A member of the state legislature has expressed concern about the differences in the mathematics test scores of high school freshmen across the state.She asks her research assistant to conduct a study to investigate what factors could account for the differences.The research assistant looks at a random sample of school districts across the state and used the factors of percentage of mathematics teachers in each district with a degree in mathematics,the average age of mathematics teachers,and the average salary of mathematics teachers.

In comparing regression models,the regression model with the largest R² will also have the smallest standard error (s).

A member of the state legislature has expressed concern about the differences in the mathematics test scores of high school freshmen across the state.She asks her research assistant to conduct a study to investigate what factors could account for the differences.The research assistant looks at a random sample of school districts across the state and uses the factors of percentage of mathematics teachers in each district with a degree in mathematics,the average age of mathematics teachers,and the average salary of mathematics teachers.

In multiple regression analysis,a desirable residual plot has what type of appearance?

Adding any independent variable to a regression model will increase ____________.

Below is a partial multiple regression ANOVA table.

A member of the state legislature has expressed concern about the differences in the mathematics test scores of high school freshmen across the state.She asks her research assistant to conduct a study to investigate what factors could account for the differences.The research assistant looks at a random sample of school districts across the state and uses the factors of percentage of mathematics teachers in each district with a degree in mathematics,the average age of mathematics teachers,and the average salary of mathematics teachers.

A multiple regression model with four independent variables consists of 29 observations.The multiple coefficient of determination R² = .80,and the standard error s = 2.0.Complete the analysis of variance table for this model,and test the overall model for significance.

If the multiple coefficient of determination that relates x₃ to all the other independent variables,R²(x₃)= .8,calculate the variance inflation factor for x₃.Should the analyst be concerned about multicollinearity? Why or why not?

If the simple correlation coefficient between two independent variables is greater than .90,then ______________________ is considered to be severe.

The management of a professional baseball team is in the process of determining the budget for next year.A major component of future revenue is attendance at the home games.In order to predict attendance at home games,the team statistician has used a multiple regression model with dummy variables.The model is of the form y = β₀ + β₁x₁ + β₂x₂ + β₃x₃ + ε,where: y = attendance at a home game. x₁ = current power rating of the team on a scale from 0 to 100 before the game. x₂ and x₃ are dummy variables,and they are defined below. x₂ = 1,if weekend, x₂ = 0,otherwise. x₃ = 1,if weather is favorable, x₃ = 0,otherwise. After collecting the data,based on 30 games from last year,and implementing the above stated multiple regression model,the team statistician obtained the following least squares multiple regression equation:

Below is a partial multiple regression ANOVA table.