What signifies a mean deviation of zero?

A mean deviation of zero suggests that every data point in a dataset is identical to the mean value of that dataset. In the context of property assessments, if all properties are assessed equally, it means that the assessment value for each property is the same, leading to no deviation from this established mean. Thus, all deviations from the mean would amount to zero.

This concept indicates uniformity in assessments, implying that the values assigned do not vary, which aligns directly with the definition of mean deviation. In contrast, scenarios where market prices or properties vary greatly would not result in a mean deviation of zero. For example, if there were significant differences in market prices or assessments, deviations would manifest, preventing the mean deviation from being zero.