A magnesium test checks the level of magnesium in the blood. Magnesium is an important electrolyte needed for proper muscle, nerve, and enzyme function. It also helps the body use energy and is needed to move other electrolytes (potassium and sodium) into and out of cells.
Floors in Pricing. A price floor is the lowest amount at which a good or service may be sold and still function within the traditional supply and demand model. Prices below the price floor do not result in an appropriate increase in demand.
1 The most important example of a price floor is the minimum wage. 2  A price ceiling is a maximum price that can be charged for a product or service. 3  Rent control imposes a maximum price on apartments in many U.S. cities. 4  A price ceiling that is larger than the equilibrium price has no effect.