A research analyst examines annual returns (in percent) for Industry A, Industry B, and Industry C, as shown in the accompanying table.

Industry A.................... Industry B........................... Industry C

16.86.................................. 15.41....................................13.53

5.11.................................. . 10.87.................................... 9.58

12.45.................................. 4.43.................................... 18.75

-32.44............................... -18.45...................................-28.77

32.11.................................. 20.96....................................32.17

a. Specify the competing hypotheses to test whether some differences exist in the median returns by industry.

b. Calculate the value of the test statistic H.

c. At the 10% significance level, what is the critical value?

d. Do some differences exist between the median returns by industry? Explain.