Suppose that a random sample of five active members in each of four political parties in a certain western European country was given a questionnaire purported to measure (on a 100-point scale) the extent of "general authoritarian attitude toward interpersonal relationships." The means and standard deviations of the authoritarianism scores for each party are given in the following table.

a. Determine the appropriate ANOVA table for this data set.
b. Test to see whether significant differences exist among parties with respect to mean authoritarianism scores.
c. Using dummy variables, state an appropriate regression model for this experimental situation.
d. Apply the Tukey-Kramer method of multiple comparisons to identify the pairs in which the means significantly differ from one another. (Use α = .05.)