1. AP Statistics Chapter 15 Notes

2. Inference for a Regression Line Goal: To determine if there is a relationship between two quantitative variables. –i.e. What is the slope of the regression line? –From sample…a and b are statistics –True regression line…α and β are parameters.

3. Conditions 1. Observations are independent. 2. True relationship is linear. 3. σ is constant. –Check residual plot…make sure there is no pattern and the magnitude of the residuals is stable. 4. Response varies Normally about the true regression line. –Make histogram or stemplot of residuals.

4. Confidence Intervals & Significance Tests Confidence Interval: (estimate β) b ± t* SE b (df = n – 2) Significance Test H o : β = 0t = b/SE b H a : β ≠ > < 0