The researchers in Exercise 23 also examined the of people admitted to emergency rooms for vehicular accidents on 12 Friday evenings (6 each on the 6th and 13th). Is Friday the 13th "unlucky"? Hospital emergency rooms need to plan for any increased "business" if they can. Use an appropriate nonparametric test to decide whether there is really a difference between consecutive Fridays when one of them is a 13th.