Which statistic is specifically a measure of variability?

Which statistic is specifically a measure of variability?

• A. Mean
• B. Median
• C. Mode
• D. Standard Deviation

Answer: (D)

Understanding how spread out data are is what this question emphasizes. The statistic that captures that spread is the standard deviation. It reflects, on average, how far each data point lies from the mean. A small standard deviation means the values are clustered near the mean, while a large one indicates greater dispersion across the data set. The other commonly used numbers describe central tendency rather than variability: the mean is the average value, the median is the middle value when the data are ordered, and the mode is the most frequent value. These tell you where values tend to lie overall, not how spread out they are, which is why standard deviation is the measure of variability.

Understanding how spread out data are is what this question emphasizes. The statistic that captures that spread is the standard deviation. It reflects, on average, how far each data point lies from the mean. A small standard deviation means the values are clustered near the mean, while a large one indicates greater dispersion across the data set. The other commonly used numbers describe central tendency rather than variability: the mean is the average value, the median is the middle value when the data are ordered, and the mode is the most frequent value. These tell you where values tend to lie overall, not how spread out they are, which is why standard deviation is the measure of variability.