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.
They are flat, with no holes. The Sea Biscuit Sand Dollar. They are puffy and not normally the type of Sand Dollars people think of. The Arrowhead Sand Dollars got their name from the shape that looks a bit like an arrowhead. The Key Hole Sand Dollar is the one I think of when I think of Sand Dollars. When I was a little girl, I heard a story about the special meaning of this type of San Dollar. Ever since then, I have not been able to look at San Dollar without remembering that story.