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.
Donax variabilis Say, 1822. Wedge (or Bean) clams are found in the sand of almost every tropical or temperate beach around the world. The Atlantic Coquina, Donax variabilis, is found on beaches in the Southeastern United States. The clam is no longer than half of an inch.