Amira has a pyramid shaped plant pot. It has a square base with a side length of 30\text{ cm}30 cm30, start text, space, c, m, end text, and the height of the pot is 30\text{ cm}30 cm30, start text, space, c, m, end text. Amira wants to fill the pot to \dfrac12 2

1



start fraction, 1, divided by, 2, end fraction of its height with soil.

What is the approximate volume of soil that Amira needs?

Round to the nearest cubic centimeter.

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.