A research analyst wants to test whether the unemployment rate differs from one region of the country to another. She collects the unemployment rate (in percent) of similar-sized cities in three regions of the United States. The results are shown in the accompanying table, and are also available on the text website, labeled Regional Unemployment.
a. Specify the competing hypotheses in order to test whether differences exist in the median unemployment rate between the three regions.
b. Calculate the value of the test statistic H.
c. At the 10% significance level, what is the critical value?
d. Does the unemployment rate differ by region? Explain.