•in a rectangular pyramid:
cross sections parallel to the base take the shape of
cross sections perpendicular to the base, through the top vertex, take the shape of
cross sections perpendicular to the base, not through the top vertex, take the shape of .

D.) Sample means will vary because the data values selected for each sample will be different.

[ It is like the large pool, so if you pick some fishes from certain area might be very different from the fish of another area, in the same pool ]

Hope this helps!