Which statement describes ratio data?

• A. Data measured with equal intervals and a true zero
• B. Data with order but no equal intervals
• C. Categorical data
• D. Data with ranks only

Answer: (A)

Ratio data means the numbers reflect quantities with equal spacing between values and a true zero point, so zero truly means none of the quantity and you can meaningfully compare magnitudes and form ratios (one value can be twice another). Examples include height in centimeters, weight in kilograms, time durations, and income. The equal intervals allow consistent differences, and the true zero allows ratio statements like "twice as much." This differs from interval data, which has equal intervals but an arbitrary zero (no true absence), so you can discuss differences but not meaningful ratios. Ordinal data shows order without equal intervals, and purely categorical data has categories with no inherent order. Hence, the statement describing ratio data is data measured with equal intervals and a true zero.