1/23/2013

Questions from Chapter 0

Simple Linear Regression - See Chpt1, Sec1.2, 1.3.ppt

• Purpose
• Functional versus statistical relationship
• Formal Model
• Method of Least Squares
• Assumptions
  • Normality
  • Independence
  • Homogeneity of variance
• Estimation of variability about the regression line
  • Residuals
    • Residual = observed - predicted
  • MSE
• Assessing the fit
  • Residual plots (used to check assumptions)
    • Plot residuals against explanatory variable and other available variables
    • Construct a normal probability plot for the residuals

Example with R - Open P:\data\math\hartlaub\datanalysis\PorschePrice.R

In class exercises

• 1.17, 1.19, and 1.21

Please complete your reading of Chapter 1 for class on Friday.