During a medical emergency, people who dial 911 expect an ambulance to arrive quickly and personnel to provide vital care. Health insurance companies believe there is a marked difference in the...

During a medical emergency, people who dial 911 expect an ambulance to arrive quickly and personnel to provide vital care. Health insurance companies believe there is a marked difference in the response time for rural areas versus cities because of differences in coverage area and number of qualified paramedics. Random samples of ambulance response times (in minutes) were obtained for rural areas and cities.

 a. Assuming normality, find a 99% confidence interval for the true mean response time for rural-area ambulances.

 b. Assuming normality, find a 99% confidence interval for the true mean response time for city ambulances.

c. Use the methods described in Section 6.3, page 272, to determine whether there is any evidence to suggest either response time distribution is non-normal. d. Is there any evidence to suggest the mean response time is different for rural areas and cities? Justify your answer.