Aschool district is considering whether it will no longer allow students to park at school after two recent accidents where students were severely injured. as a first step, they survey parents of high school students by mail, asking them whether or not the parents would object to this policy change. of 5,799 surveys that go out, 1,209 are returned. of these 1,209 surveys that were completed, 926 agreed with the

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.