Teen smoking, part II Consider again the Vermont study discussed in Exercise 23. a) Create a 95% confidence interval for the difference in the proportion of children who may smoke and have lenient parents and those who may smoke and have disapproving parents. b) Interpret your interval in this context. c) Carefully explain what 95% confidence means.

Week 15: ANOVA 13 December 2016 Basic Statistics for Research Professor HK Dong Analysis of Variance (ANOVA) – hypothesis testing procedure used to evaluate differences between the means of two or more treatments or groups (populations) Uses sample data to make inferences about populations Determine the amount of variability in groups of data, and to see if the variability is greater between groups or within groups Different treatment groups: Total Variability: Deviation = Sum of squared total: Treatment Variability: Deviation = Sum of squared treatment: Error Variability: Deviation = Sum of squared error: Total Variation (SS total= variation due to factor + variation due to random sampling aka: