15.29 Traffic Control Two methods for controlling traffic, A and B, were used at each of n = 12...

15.29 Traffic Control Two methods for controlling traffic, A and B, were used at each of n = 12 intersections for a period of 1 week, and the numbers of accidents that occurred during this time period were recorded. The order of use (which method would be employed for the first week) was selected in a random manner. You want to know whether the data provide sufficient evidence to indicate a difference in the distributions of accident rates for traffic control methods A and B.

Â	Method	Â	Method
Intersection	A	B	Intersection	A	B
1	5	4	7	2	3
2	6	4	8	4	1
3	8	9	9	7	9
4	3	2	10	5	2
5	6	3	11	6	5
6	1	0	12	1	1

a. Analyze using a sign test.

b. Analyze using the Wilcoxon signed-rank test for a paired experiment.