With over $18 billion in debt, in July 2013 the city of Detroit declared bankruptcy. In many parts of the city there are few public services, roads in need of repair, and approximately 40% of all streetlights do not work at night. In addition, the mean police response time is 58 minutes.74 A random sample of calls to police was obtained and the response time (in minutes) for each was recorded. The data are given in the following table.
a. The chief of police claims that response time has improved. Is there any evidence to suggest that the mean police response time has decreased? Assume normality and use a 5 0.05.
b. Find bounds on the p value for this hypothesis test.