How should zip codes be classified in terms of attributes?

Zip codes should be classified as categorical because they are used to identify specific geographical areas rather than to represent quantities. While zip codes consist of numerical digits, they do not convey any inherent numerical value; rather, they serve as labels that categorize different regions for purposes such as mail delivery and location.

Categorical data are those that can be sorted into groups or categories, and zip codes fit this definition well since they group locations without indicating any quantitative measurement. It's important to note that, although zip codes are composed of numbers, manipulating them mathematically (such as adding or averaging) does not provide meaningful results in relation to the geographical categories they represent.

In contrast, the other classifications involve types of numerical data or qualities that do not apply to zip codes. This is what reinforces the idea that zip codes are best understood as categorical data.