Question: “The phenomenon of road rage has been frequently discussed but infrequently examined.” So begins a report based on interviews with randomly selected drivers. The respondents’ answers to interview question produced scores on an “angry/threatening driving scale” with values between 0 and 19. Here are summaries of the scores:

Group n \[\overline{x}\] s

Male 596 1.78 2.79

Female 769 0.97 1.84

(a) We suspect that men are more susceptible to road rage than women. Carry out a test of the hypothesis (State hypotheses, find the test statistic and P value, and state your conclusion)

(b) The subjects were selected using random-digit dialing. The large sample sizes make the Normality condition unnecessary. There is one aspect of the data production that might reduce the validity of the data. What is it?