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.
Concrete sand is a coarse to very coarse sand with particle size ranges from 0.30 to 2.00 millimeters. It is a good choice for improving drainage in soil or installing a new septic system. Use it to improve drainage of clay soil by adding a 1 inch layer to the surface and working it in to a depth of at least 6 inches.