Standard deviation is a measure of this.

Standard deviation is a measure of this.

• A. Variability
• B. Central tendency
• C. Correlation
• D. Probability

Answer: (A)

Standard deviation measures how spread out the data are around the average. It captures variability or dispersion in a dataset: a small standard deviation means values are clustered close to the mean, while a large one indicates values spread far from the mean. It’s related to variance—one is the square root of the other—and it shares the same units as the data, making interpretation more intuitive. This concept is distinct from central tendency, which describes the typical value (mean, median, or mode), and from correlation (the relationship between two variables) or probability (likelihood of outcomes). In a normal distribution, about 68% of values fall within one standard deviation of the mean, about 95% within two, and about 99.7% within three, illustrating how standard deviation governs the spread.

Standard deviation measures how spread out the data are around the average. It captures variability or dispersion in a dataset: a small standard deviation means values are clustered close to the mean, while a large one indicates values spread far from the mean. It’s related to variance—one is the square root of the other—and it shares the same units as the data, making interpretation more intuitive. This concept is distinct from central tendency, which describes the typical value (mean, median, or mode), and from correlation (the relationship between two variables) or probability (likelihood of outcomes). In a normal distribution, about 68% of values fall within one standard deviation of the mean, about 95% within two, and about 99.7% within three, illustrating how standard deviation governs the spread.