Differentiate fixed costs and variable costs. 1  Total cost is the sum of fixed and variable costs.  Variable costs change according to the quantity of a good or service being produced. The amount of materials and labor that is needed for to make a good increases in direct proportion to the number of goods produced.
Southern Copper Corporation is an American-based copper producer with major operations in Mexico and Peru. Grupo Mexico currently owns 75.1% of the company, which produced 487 thousand metric tons of copper in 2010. Major assets include the Cuajone and Toquepala mines in Peru and the Cananea mine in Mexico.
Coming in at the No.10 spot is the Laramide Porphyry copper cluster of Arizona, New Mexico and Sonora (Mexico). The Morenci open pit, located in southwest Arizona, is the largest copper-producing operation in North America, and majority owner Phelps Dodge Corp. has been mining this rich deposit since the 1880s.