Which question can best be answered by finding the surface area of a figure?
How much water is needed to fill a pool?
How much paint is needed to paint a cube?
How far will a car drive around an oval race track?
How much concrete is needed to make a decorative tile for a garden?

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.