12. The local regional transit authority of a large city was interested in determining the mean commuting time for workers who drive to work. They selected a random sample of 125 workers who drive to work and asked them how long they spent commuting to work (in minutes). A 95% confidence interval was constructed and reported as (27.74, 30.06). (a) Show that the conditions for calculating a confidence interval for a mean are satisfied. (b) Interpret the interval in the context of this