However, this does not take into consideration the variation in scores amongst the 50 students (in other words, the standard deviation). After all, if the standard deviation is 15, then there is a reasonable amount of variation amongst the scores when compared with the mean.
Quick Answer. Macrominerals are inorganic nutrients that the human body requires in large quantities because they carry out several critical bodily functions. The most important macrominerals include potassium, calcium, magnesium, sodium, chloride, sulfur and phosphorus.
Emery stone is a granular metamorphic or igneous rock that is rich in corundum. It is a mixture of oxide minerals, typically corundum, magnetite, spinel and/or hematite. It is the most common form of natural corundum that has been used to manufacture abrasives.The use of emery as an abrasive has declined significantly in the last several decades.ost people are familiar with corundum; however, very few people know it by its mineral name-instead they know it by the names ruby and sapphire.. A gemstone-quality specimen of corundum with a deep red color is known as a ruby..