2/22/2017

Chapter 7 Multiple Regression II

• Type I Sums of Squares
  • Example - Return to Body Fat - See Tables 7.1 and 7.2 and Bodyfat.R
• Type II Sums of Squares
• Using extra sums of squares to test hypotheses for betas
  • Full versus reduced model approach
• Coefficients of partial determination
• Standardized multiple regression model -
  • See Table 7.5 and Dwaine-Studios.R
  • Verify that the results from lm.beta match those obtained with the fitted standardized model by creating the transformed variables and finding the appropriate estimates with lm.
• Multicollinearity

Chapter 8 Polynomial Regression Models

• Discussion of quadratic, cubic, and higher order models.
• To avoid problems with multicollinearity, center the predictor variables
  • See Table 8.1 and Powercell.R
• Modify Bodyfat.R to fit the model in 8.29 on page 312

We will have a problem session on Friday.