Which type of variable includes both discrete and continuous forms?

Quantitative variables are those that can be measured and expressed numerically. They can be divided into two subcategories: discrete and continuous. Discrete variables are countable and can only take on specific values, such as the number of students in a classroom, while continuous variables can take on any value within a given range, such as height or weight. This means that quantitative variables encompass both forms, making them a broad category used for various types of measurements.

In contrast, qualitative variables describe characteristics or qualities that are typically categorical in nature, such as colors or types of animals, and do not include numerical measurement. Nominal variables, a type of qualitative variable, refer specifically to categories without a specific order, like gender or ethnicity. Ordinal variables, also qualitative, involve categories with a meaningful order but do not quantify the difference between levels, such as rankings in a race. Hence, the identification of quantitative variables as including both discrete and continuous forms accurately reflects their definition and function in statistics.