A number of minor automobile accidents occur at various high-risk intersections 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 a proposed experiment. Eight intersections were chosen at random, and the lights at those intersections were modified. The numbers of minor accidents during a 6-month period before and after the modifications were:

At the .01 significance level, is it reasonable to conclude that the modification reduced the number of traffic accidents?

a. What are the null and alternate hypotheses?

b. Compute the test statistic.

c. Compute the p-value.

d. What is your decision regarding the null hypothesis?

e. Interpret the result.

Transcribed Image Text:

Number of Accidents A D E F G H Before modification 7 6 4 8 9 10 After modification 3 7 7 4 6 8 2 B.