Which scale has a true zero and allows all arithmetic operations including multiplication and division?

Which scale has a true zero and allows all arithmetic operations including multiplication and division?

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

Answer: (C)

Ratio scales provide a true zero point, which means the zero represents a complete absence of the quantity, and the scale supports all arithmetic operations, including multiplication and division. With a true zero, you can meaningfully say that one value is twice another, half as much, or three times as long as another. Examples include weight in kilograms, height in centimeters, duration in seconds, and distance in meters. In contrast, an interval scale has equal intervals but an arbitrary zero (such as Celsius temperatures), so ratios aren’t meaningful even though you can add and subtract. Nominal scales categorize data without intrinsic order, so arithmetic isn’t appropriate. Ordinal scales establish order but don’t have equal intervals, so you can say which value is larger, but not by how much or that one value is a fixed multiple of another.

Ratio scales provide a true zero point, which means the zero represents a complete absence of the quantity, and the scale supports all arithmetic operations, including multiplication and division. With a true zero, you can meaningfully say that one value is twice another, half as much, or three times as long as another. Examples include weight in kilograms, height in centimeters, duration in seconds, and distance in meters.

In contrast, an interval scale has equal intervals but an arbitrary zero (such as Celsius temperatures), so ratios aren’t meaningful even though you can add and subtract. Nominal scales categorize data without intrinsic order, so arithmetic isn’t appropriate. Ordinal scales establish order but don’t have equal intervals, so you can say which value is larger, but not by how much or that one value is a fixed multiple of another.