The number of drinks consumed in a night is best described as which level of measurement?

The number of drinks consumed in a night is best described as which level of measurement?

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

Answer: (D)

Measurement scales determine what arithmetic makes sense for a variable. The number of drinks consumed in a night is a count: it has uniform units (one drink each) and, crucially, a true zero—having zero drinks means there were none. Because of that true zero, you can meaningfully add, average, and compare ratios (for example, someone who drank four drinks consumed twice as many as someone who drank two). That combination—true zero plus meaningful ratios and equal intervals—places this variable on the ratio level of measurement. It isn’t just categories or an ordered ranking, and the zero in this case represents an actual absence, which distinguishes it from interval scales where zero is not a true absence.

Measurement scales determine what arithmetic makes sense for a variable. The number of drinks consumed in a night is a count: it has uniform units (one drink each) and, crucially, a true zero—having zero drinks means there were none. Because of that true zero, you can meaningfully add, average, and compare ratios (for example, someone who drank four drinks consumed twice as many as someone who drank two). That combination—true zero plus meaningful ratios and equal intervals—places this variable on the ratio level of measurement. It isn’t just categories or an ordered ranking, and the zero in this case represents an actual absence, which distinguishes it from interval scales where zero is not a true absence.