The Morgan Quitno Press regularly ranks U.S. states on how "smart" they are based on 21 criteria including per-student school expenditures, percent of population with high school degrees, high school dropout rate, average class size, and "percent of 4th graders whose parents have strict rules about getting homework done." Here are the rankings for all 50 states for 2004.
We marked states in the Northeast with an NE, in the Midwest with a MW, and in the South with an S. Do these regions tend to have different rankings from one another?
a. What is the independent variable and what are its levels? What is the dependent variable?
b. Is this a between-groups or within-groups design? Explain.
c. Why do we have to use a nonparametric hypothesis test for these data?
d. Conduct all six steps of hypothesis testing for a Kruskal-Wallis H test. Note that you have to rank just the states in this study, separate from the original ranking list.
e. How would you present these statistics in a journal article?
f. Explain why a statistically significant Kruskal-Wallis H statistic does not tell us exactly where the specific differences lie. If there is a statistically significantfinding for this example, determine where the difference lies by calculating Kruskal-Wallis H statistics for each pair.