Alice can run a lap in 141/10 seconds; Betsy can run a lap in 235/14 seconds; and Casey can run a lap in 94/7 seconds. They start running together at the same time at point A. Wehn Alice, Betsy, and Casey meet for the first time at point A, how many laps would Alice have ran

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.