In the book Harry Potter and the Millennials, political scientist Anthony Gierzynski examines whether reading Harry Potter has influenced the political views of the hundreds of millions of millennials who have read the books in the series.

Imagine that we divided a sample of millennials into five categories of exposure to Harry Potter books: (1) never read Harry Potter, (2) started but never finished a Harry Potter book, (3) read one Harry Potter book, (4) read more than one Harry Potter book but not all of them, and (5) read all of the Harry Potter books.

Table 11.11 shows mean scores for each of the five groups on a scale measuring political ideology, where 1 means extremely liberal, 7 means extremely conservative, and 4 is neutral.

a. Do the mean differences shown in Table 11.11 suggest that exposure to Harry Potter is related to political ideology? What does the effect of Harry Potter appear to be on political ideology?

b. A software program produced the findings from an ANOVA test of differences in political ideology by Harry Potter exposure shown in Table 11.12.
What is the null hypothesis being tested here?

c. What do the ANOVA results indicate about mean differences in political ideology by Harry Potter exposure?

d. What do we learn about the sample of millennials from Table 11.12 that we could not know from Table 11.11?