A wall of a building is made from blocks that are each 1 cubic foot. The wall is 6 feet high and 6 feet wide.
A window is made by removing some blocks as shown below.
The window is 2 feet high by 2 feet wide.

The wall is 6 feet high and 6 feet wide. The window is 2 feet high by 2 feet wide is cut from the centre of the wall.

What is the volume of the wall after the window is made? Enter your answer in the box.

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.