Point B is halfway between A and C. The distance from C to D is the same as the distance from D to E, which is the same as the distance from E to F. The area of triangle ACF is 180 cm². How many square centimeters is the shaded area of triangle BCE?

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.