Abby made a goal to run a half marathon with her sister. She ran 1,354 yards the first week. She ran 3,281 yards the second week. How many more yards did Abby run on the second week than the first week? Abby ran more yards the second week.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.