Psychology and Human Behavior

Two recent studies suggest that people who drive really nice cars exhibit some very bad habits. In one study, as a car approached a crosswalk, a person stepped into the road, and the driver's reaction was recorded. In another, similar study, independent random samples of drivers were selected, and their behavior was observed at a four-way intersection.

For luxury-car drivers, n₁ = 217 and 130 cut ahead in the usual four-way rotation.

For ordinary-car drivers, n₂ = 182 and 82 violated the four-wayintersection rotation rule.

Is there any evidence to suggest that the proportion of luxury-car drivers with insufferable driving habits is greater than the proportion of ordinary-car drivers with similar habits? Use a = 0.01.

Note: The largest group of driving-rule etiquette violators were men, ages 35-50, with blue BMWs.