Randomly selected 60 student cars have ages with a mean of 7.8 years and a standard deviation of 3.4 years, while randomly selected 105 faculty cars have ages with a mean of 6 years and a standard deviation of 3.5 years.

1. Use 0.02 significance level to test the claim that student cars are older than faculty cars.

a) The test statistic is ______

2. Construct a 98% confidence interval estimate of the difference u1-u2 where u1 is the mean age of student cars and u2 is the mean age of faculty cars

a) _________________ <(u1-u2)<___________________