Which data type is characterized by a meaningful zero point and allows the calculation of ratios?

The data type that is characterized by a meaningful zero point and allows for the calculation of ratios is the ratio scale. This scale not only possesses the characteristics of an interval scale—where differences between measurements are meaningful and quantifiable—but also includes a true zero point that signifies the absence of the quantity being measured.

For example, in the context of height, a height of zero means no height at all, which is a meaningful point in measurement. This allows for meaningful ratios, such as saying that a person who is 180 cm tall is twice as tall as someone who is 90 cm tall. This property of being able to express values in terms of ratios, such as "twice" or "three times", distinguishes the ratio scale from other types of data.

In contrast, nominal data refers to categories without a meaningful order (like gender or ethnicity), ordinal data involves a meaningful order but no consistent difference between levels (like rankings), and interval data has meaningful differences but lacks a true zero point (like temperature in Celsius or Fahrenheit). Therefore, the defining characteristic of a meaningful zero point coupled with the capacity for ratio calculations firmly supports that the correct answer is the ratio data type.