Jadyn is taking an exam on the computer. as she answer each question, the progress bar at the bottom of the screen show what portion of the trst she has completed. she has just answered questions 16 and the progress bar shiws she is 20% complete. how many total questions are in the test, pleae

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.