An identification number, such as student or customer ID, is an example of which type of variable?

An identification number, such as a student or customer ID, is classified as a qualitative variable because it represents categorical data rather than numerical values. Qualitative variables, also known as categorical variables, are used to describe characteristics or qualities that can be grouped but do not measure quantities.

In the case of identification numbers, they serve to label or identify individuals within a specific dataset but do not quantify or provide measurable insights about the individual’s attributes. For instance, the number "12345" assigned to a student is simply a label and does not convey any intrinsic numerical value or rank, which is characteristic of qualitative data.

Quantitative variables, in contrast, involve measurable quantities, continuous variables can take any value within a range, and discrete variables represent countable items. Since identification numbers do not fit into these categories, the correct classification is as a qualitative variable.