Variable costs are expenses that vary in proportion to the amount of goods or services that a business produces. 

Examples of variable cost include labor, packaging and raw materials.

Value added is determined by the difference between the price of product or service and the cost of producing it.

Added Value = Price that the product or service is sold at - cost of producing the product.

Emotional intelligence is a critical component of social intelligence.

Standard deviation measures total risk in stocks.

Tax that uses the same rate for all income levels is proportional tax.

Phage typing is based on the fact that bacterial viruses attack specific cells. Phage typing is a method used for detecting single strains of bacteria. It is used to trace the source of outbreaks of infections.