An Egyptian pharaoh has ordered the construction of four square pyramids. The main pyramid will be the tallest, while the other 3 will each be half its height. All four pyramids must have a height to base length ratio of 2:3. The pharaoh has allocated a maximum amount of 30 million cubic feet of stone for construction.
Find the largest possible values for the base length and height, to the nearest foot, as well as the volume of each pyramid, in scientific notation to 3 decimal places.