Statistics and Probability Dictionary
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Variables can be classified as categorical (aka, qualitative)
or quantitative (aka, numerical).
Categorical. Categorical variables take on values that are names
or labels. The color of a ball (e.g., red, green, blue) or the
breed of a dog (e.g., collie, shepherd, terrier) would be examples
of categorical variables.
Quantitative. Quantitative variables are numerical. They represent a
measurable quantity. For example, when we speak of the
population of a city, we are talking about the number of people
in the city - a measurable attribute of the city. Therefore,
population would be a quantitative variable.
In algebraic equations, quantitative variables are represented by
symbols (e.g., x, y, or z).