Which statement describes interval data?

• A. Values are categories with no inherent order
• B. Values have a true zero point
• C. Equal intervals between consecutive values
• D. Values are ranked with unequal distances

Answer: (C)

Interval data are numeric values that have equal spacing between consecutive values. This equal interval means differences are meaningful and consistent across the scale, so you can compare how much two values differ and compute averages. For example, in the Celsius scale, the change from 10° to 20° is the same interval as from 30° to 40°. However, there isn’t a true zero that indicates “no temperature,” so ratios (like 40° being twice 20°) aren’t meaningful. Other data types either use categories with no inherent order, have a true zero that allows ratios, or are ordered but with unequal gaps between values.