Which data type is best described as having an inherent order but no meaningful arithmetic operations?

• A. Ordinal data
• B. Nominal data
• C. Interval data
• D. Ratio data

Answer: (A)

The thing being described is ordinal data: you can rank or order the categories, but the intervals between them aren’t meaningful for arithmetic. You can tell that one category is higher or lower than another, but you can’t quantify the exact difference or perform reliable calculations on the values.

Think of a rating scale like poor, fair, good, excellent. There’s a clear order, but the jump from fair to good isn’t guaranteed to be the same as from good to excellent, so adding or averaging these numbers isn’t meaningful.

Nominal data would have categories without any inherent order, so you couldn’t say one category is higher than another. Interval data has ordered categories with equal intervals, so you can do arithmetic (like adding and subtracting), but there’s no true zero. Ratio data has a true zero and supports all arithmetic operations, including meaningful ratios.