Insurance adjusters are concerned about the high estimates they are receiving for auto repairs from  garage I compared to grage II. To verify their suspicions, each of the 15 cars recently involved in an accident was taken to both garages for separate estimates of repair costs. The estimates are given: At a significance level of 5%, answer the following questions? 

a. Are the charges at the two garages different?

b. Is Garage I charging more than Garage II? 

c. The same car was taken to both garages. If that information is not known, will the conclusions differ? Use Excel and check your answers with Minitab.