A survey of asked respondents how long (in years) they thought it would be before self driving cars were the majority of vehicles on the road, and a random sample from this survey was selected. The data are available at the text’s website.

a. Find a 95% confidence interval for the difference in mean lengths of time before self driving cars are the majority of vehicles on the road between males and females.

b. Use a significance level of 0.05, test the hypothesis that the mean lengths of time for males and females are significantly different.