The administrator of the National Highway Traffic Safety Administration (NHTSA) wants to know if the different types of vehicles in a state have a relationship to the highway death rate in the state. She has asked you to perform several regression analyses to determine if average vehicle weight, percentage of imported cars, percentage of light trucks, or average car age is related to crash deaths in automobiles and pickups. The data for the analyses are in the data file Vehicle Travel State. The variable descriptions and locations are contained in the Chapter 11 appendix.
a. Prepare graphical plots of crash deaths versus each of the potential predictor variables. Note the relationship and any unusual patterns in the data points.
b. Prepare a simple regression analysis of crash deaths on the potential predictor variables. Determine which, if any, of the regressions indicate a significant relationship.
c. State the results of your analysis and rank the predictor variables in terms of their relationship to crash deaths.