Lesson Objectives. 1  List the main features of the seafloor: mid-ocean ridges, deep sea trenches, and abyssal plains. 2  Describe what seafloor magnetism tells scientists about the seafloor. 3  Describe the process of seafloor spreading.
Assignment Help. The average diameter of sand dollars on a certain island is 4.50 centimeters with a standard deviation of 1.00 centimeters. If 9 sand dollars are chosen at random for a collection, find the probability that the average diameter of those sand dollars is more than 4.13 centimeters.he average diameter of sand dollars on a certain island is 4.50 centimeters with a standard deviation of 1.00 centimeters.
Round. Sand is defined by its size rather than what type of mineral it is. Particle size or grain size refers to the diameter of a grain of granular material. Technically, particles that fall between one-sixteenth of a millimeter to two millimeters in diameter are referred to as Sand.article size or grain size refers to the diameter of a grain of granular material. To determine a sand granule size, a sample is vibrated through a set of sieves of known mesh sizes. For sand the mesh size of the sieve can range from a No. 10 sieve which is 2 mm to a No. 200 sieve which is .075 mm mesh size.