One indication of morale in county government positions is the length of service in the current position. Independent random samples of county employees were obtained, and the length of service (in years) was recorded for each person, by job classification .
a. Assume the underlying distributions are continuous. Use the Kruskal-Wallis test with a = 0.05 to show that there is evidence to suggest that at least two populations are different.
b. Which pair(s) of populations do you think is (are) different? Why?
In 2013 there were 1087 supernovae reported by various observation posts around the world. When possible, these exploding stars were classified by their light curves and absorption lines. A random sample of these Type I and Type II supernovae were obtained, and the magnitude of each was recorded.24
a. Assume the underlying distributions are continuous. Use the Kruskal-Wallis test with a = 0.01 to determine if there is any evidence that the populations are different. Find the p value associated with this test.
b. Use the normal approximation in the Wilcoxon rank-sum test to determine whether there is any evidence to suggest the population median magnitudes are different. Use a = 0.01. Find the p value associated with this test.
c. What is the relationship between the p values in parts (a) and (b)? d. Consider the value of the test statistics found in parts (a) and (b). Compare z 2 and h. How are these values related?