Which option is an example of ratio-level measurement?

• A. Temperature in Celsius
• B. Number of pets
• C. Eye color
• D. Movie ratings

Answer: (B)

Ratio-level measurement means numbers with a true zero point and equal intervals, so you can compare magnitudes using multiplication and division. The option describing a count of pets fits this because it’s a count that can be zero (no pets) and you can say, for example, one person has twice as many pets as another. Temperature in Celsius has equal intervals but zero does not represent the absence of temperature, so ratios aren’t meaningful. Eye color is a label with no inherent order, making it nominal. Movie ratings are ordered but the intervals between levels aren’t necessarily equal, so ratios don’t have a consistent meaning. Therefore, the count of pets is the ratio-level example.