Name the four levels of measurement and give an example for each.

• A. Nominal (height), ordinal (IQ score), interval (income), ratio (age).
• B. Nominal (gender), interval (class rank), ordinal (IQ), ratio (time).
• C. Nominal (gender), ordinal (education level), interval (temperature), ratio (weight).
• D. Nominal (gender), ordinal (class rank), interval (IQ), ratio (height).

Answer: (D)

Four levels of measurement differ in what the numbers convey: nominal categories have no inherent order; ordinal categories have a meaningful order but unequal spacing; interval scales have equal intervals between values but no true zero; ratio scales have equal intervals plus a true zero. Gender is a category with no order, so nominal. Class rank is ordered, but the gaps between ranks aren’t guaranteed equal, so ordinal. IQ scores are numeric with equal intervals and a scale, but there isn’t a true zero representing absence of intelligence, so interval. Height has equal intervals and a genuine zero (zero height means none), so ratio. This pairing uses standard examples for each level, making it the best choice. Other options mix up which examples fit which level (for instance, treating height as nominal or using an interval example where a ratio example would be more appropriate), leading to mismatches.