Which level of measurement consists of categories only?

• A. $\mathrm{Interval}$
• B. $\mathrm{Ordinal}$
• C. $\mathrm{Nominal}$
• D. $\mathrm{Ratio}$

Answer: (C)

Verified step by step guidance

1. Understand the four levels of measurement: Nominal, Ordinal, Interval, and Ratio, each with distinct characteristics.
2. Nominal level measurement classifies data into categories without any order or ranking; these categories are mutually exclusive and exhaustive.
3. Ordinal level measurement involves categories that have a meaningful order or ranking but the intervals between ranks are not necessarily equal.
4. Interval level measurement has ordered categories with equal intervals between values but no true zero point (e.g., temperature in Celsius).
5. Ratio level measurement has all the properties of interval measurement, plus a true zero point, allowing for meaningful ratios between values.