CNN.com reported on a 2005 study that ranked the world's cities in terms of how livable they are (http:// www .cnn.com/2005/WORLD/ europe/10/ 04/eui .survey/) using a range of criteria related to stability, health care, culture and environment, education, and infrastructure. Vancouver came out on top. For each of the following research questions, state which nonparametric hypothesis test is most appropriate: Spearman rank-order correlation coefficient, Wilcoxon signedrank test, Mann-Whitney U test, or Kruskal-Wallis H test. Explain your answers.
a. Which cities tend to receive higher rankings-those north of the equator or those south of the equator?
b. Did the top ten cities tend to change their rankings since the previous study?
c. Are the livability rankings related to a city's economic status?