Adding mileage information to roadside amenity signs (“Motel 6 in 1.2 miles”) can be helpful but might also increase accidents as drivers strain to read the detailed information at a distance. The article “Evaluation of Adding Distance Information to Freeway-Specific Service (Logo) Signs” (Transp. Engr. 2011: 782–788) provides the following information on number of crashes per year before and after mileage information was added to signs at six locations in Virginia.

a. Use a one-sample sign test to determine whether more accidents occur after mileage information is added to roadside amenity signs. Be sure to state the hypotheses, and indicate what assumptions are required.
b. Use a signed-rank test to determine whether more accidents tend to occur after mileage information is added to roadside amenity signs. What are the hypotheses now, and what additional assumptions are required?

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3 4 5 66 115 62 80 78 Location 1 2 Before 15 26 After 16 24 42 6 64 73