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.
Steps to Clean Sand Dollars: 1  Begin by allowing the sand dollars to dry for a few days. 2  Fill a bowl with one part bleach and three parts water. 3  Place the dead sand dollars into the solution and allow them to soak for a short while. Do not leave them in the solution for too long as they will become brittle.