14.4 The Police Department is interested in determining the effect of alcohol consumption on driving performance. Twelve male drivers of similar weight, age, and driving experience were randomly assigned to three groups of four. The first group consumed two cans of beer within 30 minutes, the second group consumed four cans of beer within 30 minutes, and the third group was the control and did not consume any beer. Twenty minutes later, each of the twelve took a driving test under the same conditions, and their individual scores were recorded. (The higher the score, the better the driving performance.) The results were: