Interval data is a type of quantitative data that is measured along a scale with equal intervals between values. This means that the difference between any two values is meaningful and consistent. For example, the temperature measured in degrees Celsius or Fahrenheit is interval data, as the difference between 20°C and 30°C is the same as between 30°C and 40°C. However, interval data does not have a true zero point. This means that while you can add and subtract values, you cannot make meaningful statements about ratios. For instance, 0°C does not indicate the absence of temperature; it is simply a point on the temperature scale.