A number of minor automobile accidents occur at various high-risk interactions in Teton County despite traffic lights. The Traffic Department claims that a modification in the type of light will reduce these accidents. The county commissioners have agreed to proposed experiment. Eight intersections were chosen at random, and the lights at those intersections were modified. The numbers of minor accidents during a six-month period before and after the modifications were:
At the 0.01 significance level is it reasonable to conclude that the modifaction reduced the number of traffic accidents?