Which of the following is an example of a ratio data scale?

• A. Temperature in Celsius
• B. Color categories
• C. Rating scale
• D. Weight

Answer: (D)

Ratio data scales have a true zero and equal intervals, which lets you compare magnitudes and form meaningful ratios. Weight fits this: zero weight means there is no weight, and the difference between values is consistent across the scale, so you can say one weight is twice another. Temperature in Celsius is not ratio because zero does not mean the absence of temperature, so ratios like twice as hot aren’t meaningful. Color categories are just labels with no inherent order, so they’re nominal. A rating scale is usually treated as ordinal, where order matters but equal spacing and a true zero aren’t guaranteed.