Question: Risk. A study of auto safety determined the number of driver deaths per million vehicle sales, classified by type of vehicle. The data on the next page are for 6 midsize models and 6 SUVs. Wondering if there is evidence that drivers of SUVs are safer, we hope to create a 95% confidence interval for the difference in driver death rates for the two types of vehicles. Are these data appropriate for this inference? Explain. (Ross and Wenzel, An Analysis of Traffic Deaths by Vehicle Type and Model, March 2002)
Midsize 47 54 64 76 88 97
SUV 55 60 62 76 91 109