A recent study on driving behavior examined whether the combination of high driving skills and low safety skills is dangerous. Participants were classified as high or low in driving skill based on...

A recent study on driving behavior examined whether the combination of high driving skills and low safety skills is dangerous. Participants were classified as high or low in driving skill based on responses to a driver-skill inventory, then classified as high or low in safety skill based on responses to a driver-aggression scale. An overall measure of driving risk was obtained by combining several variables such as number of accidents, tickets, tendency to speed, etc. The following data were obtained. Use a 2 x 2 ANOVA with the .05 significance level to evaluate the results.

Which of the following is one of the research hypotheses?