What distinguishes interval scales from ratio scales?

The correct choice indicates that interval scales do not have a true zero point, which is a significant distinguishing feature between interval and ratio scales. A true zero point signifies the absence of the quantity being measured, allowing for meaningful ratios between the values. For example, in temperature measured in Celsius or Fahrenheit, zero does not represent a total absence of temperature; rather, it is just a point on the temperature scale. This means that you cannot say that 20 degrees Fahrenheit is twice as warm as 10 degrees Fahrenheit, as you could with ratio scales.

In contrast, ratio scales have a true zero point and provide a complete measure of quantities. For instance, weight and height measured on a ratio scale have a true zero, meaning zero weight or height indicates a complete absence of those dimensions, facilitating meaningful comparisons such as twice the weight.

Understanding the key difference regarding the presence of a true zero point helps in distinguishing between interval and ratio scales and underscores their appropriate application in data measurement.