Which type of data includes numerical values without a true zero point?

The correct choice refers to interval data, which is characterized by numerical values that have meaningful intervals between them, but do not possess a true zero point. This means that while it is possible to measure differences between values (for example, the difference between a temperature of 20 degrees and 30 degrees is the same as from 30 degrees to 40 degrees), a zero value in this context does not indicate the absence of the quantity being measured—in the case of temperature, zero degrees does not mean there is no temperature.

This property distinguishes interval data from ratio data, which does have a true zero point that indicates the absence of the quantity being measured, allowing for meaningful comparisons such as ratios (e.g., 20 kg is twice as much as 10 kg). On the other hand, ordinal data represents categories with a defined order but does not measure intervals consistently (like rankings), and qualitative data consists of descriptive attributes without numerical values, making it unrelated to the concept of numerical scales.