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.
Sand that is scooped up from the bank of a river and is not washed or sorted in any way is known as bank-run sand. It is used in general construction and landscaping. The definition of the size of sand particles varies, but in general sand contains particles measuring about 0.0025-0.08 in (0.063-2.0 mm) in diameter.