Research the causes of related medical symptoms such as: 1  Mouth. 2  Mouth symptoms (6864 causes). 3  Mouth disease. 4  Mouth disorder. 5  Mouth pain (142 causes). 6  Ulcers (28 causes).
The most important measure of economic activity in a country, the Gross Domestic Product is the crossing point of three sides of the economy: expenditure, output, and income. As a measure of well-being of a country for international and temporal comparisons, it provides a good first approximation.
Level of measurement is important because the higher the level of measurement of a variable (note that level of measurement is itself an ordinal measure) the more powerful are the statistical techniques that can be used to analyze it.