The Georgia Student Survey file on the text CD asked students their political party affiliation (1 = Democrat, 2 = Republican, 3 = Independent) and their political ideology (on a scale from 1 = very liberal to 7 = very conservative). The table shows results of an ANOVA, with political ideology as the response variable.

a. Does the ANOVA assumption of equal population standard deviations seem plausible, or is it so badly violated that ANOVA is inappropriate?
b. Are the population distributions normal? Why or why not? Which is more important, the normality assumption or the assumption that the groups are random samples from the population of interest?
c. The next table shows 95% confidence intervals comparing pairs of means. Interpret the confidence interval comparing Republicans and Democrats.

d. Explain how you would summarize the results of the ANOVA F test and the confidence intervals to someone who has not studied statistics.

Georgia political ideology and party affiliation Polltical ideology Afllatlon Democrat Republican Independent Mean StDev 2.6250 1.0607 36 5.5000 1.0000 3.4667 0.9155 15 Source PoliticalAff Error Total DF MS 79.629 39 814 54.608 .975 40.83 0.000 56 58 134.237 Affiliations 95% CI Lower C Upper 3.65 1.71 Republican-Independent 1.43 2.03 2.64 Republican-Democrat Independent-Democrat-0.02 0.84 2.10 2.87