Friday the 13th, traffic. In 1993 the  published an article titled, “Is Friday the 13th Bad for Your Health?” Researchers in Britain examined how Friday the 13th affects human behavior. One question was whether people tend to stay at home more on Friday the 13th—an issue of great concern, for example, to restaurants and theaters. The data in the table are the number of cars passing Junctions 9 and 10 on the M25 motorway for consecutive Fridays (the 6th and 13th) for five different periods.

Identify and use an appropriate nonparametric test to judge whether there is a significant difference in traffic between consecutive Fridays when one is the 13th.