Which of the following types of variables would have a true zero point?

CONCEPT

Measurement scales differ in the comparisons they permit. A true or absolute zero represents the absence of the measured quantity; this makes ratio statements meaningful.

APPLICATION

Among nominal, ordinal, interval, and ratio scales, the ratio scale combines ordered values, equal intervals, and an absolute zero. Therefore, ratio is the required type of variable.

CONTRAST

• Nominal: classifies observations into categories without ranking them.

• Ordinal: ranks observations, but adjacent ranks need not be equally spaced.

• Interval: has equal units, but its origin is conventional, so ratios are not meaningful.

• Ratio: has equal units and an absolute zero, so both differences and ratios are meaningful.

RESULT

Ratio.