You are comparing freshmen and seniors at your college on hours spent studying per day. You pick a sample of 11 people from each group. For freshmen, the mean was 3 and the variance was 1.2. For...

You are comparing freshmen and seniors at your college on hours spent studying per day. You pick a sample of 11 people from each group. For freshmen, the mean was 3 and the variance was 1.2. For seniors, the mean was 2 and the variance was 1. Calculate a 90% confidence interval on the difference between means (freshmen - seniors). What is the lower limit of this CI?