The sum of the deviations from the mean is always A) equal to zero. B) equal to the mean. C) always positive. D) equal to the median.

The sum of the deviations from the mean is always equal to zero! This is a fundamental property of the mean in statistics. When you calculate the mean, you're finding the average, and the deviations are how far each data point is from this average. Interestingly, some values will be above the mean, and others will be below, perfectly balancing each other out to yield a sum of zero. In practice, this property is incredibly useful, especially in data analysis and research. When you analyze data, recognizing that the sum of these deviations cancels out can help you validate your results and understand the dispersion of your data. It's like a mathematical reset button, showing that the mean does indeed represent a 'central' position!