______________ scales are interval scales with an absolute zero point.

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

Answer: (C)

Ratio scales are interval scales with an absolute zero point. That means they keep the equal-interval property of interval scales, but they also have a true zero that signifies none of the quantity. With this zero element, you can interpret meaningful ratios—twice as much, half as big, etc.—which isn’t possible on pure interval scales where zero is arbitrary. For example, height in centimeters or weight in kilograms illustrate ratio scales because you can say someone is twice as tall as another or weigh half as much as someone else. In contrast, nominal scales categorize without order, ordinal scales show order without equal steps, and interval scales have equal steps but lack a true zero (like Celsius temperature, where 0 does not mean “no temperature”).