CNN.com reported on a 2012 study that ranked the world’s cities in terms of how livable they are (travel.cnn.com/explorations/ life/worlds-most-livable-city-525619), using a range of criteria related to stability, health care, culture and environment, education, and infrastructure. The top 10, in order, were: Melbourne, Australia; Vienna, Austria; Vancouver, Toronto, and Calgary, all in Canada; Adelaide and Sydney, both in Australia; Helsinki, Finland; Perth, Australia; and Auckland, New Zealand. For each of the following research questions, state which nonparametric hypothesis test is appropriate: the Spearman rankorder correlation coefficient, the Wilcoxon signed-rank test, the Mann–Whitney U test, or the Kruskal–Wallis H test. Explain your answers and indicate the equivalent parametric test. 

a. Which cities tend to receive higher rankings— those north of the equator or those south of the equator? 

b. Did the top 10 cities tend to change rank relative to their position in the previous study? 

c. Are the livability rankings related to a city’s economic status? 

d. On which continent do cities tend to have the highest rankings?