What does standard deviation measure?

What does standard deviation measure?

• A. How far scores deviate from the mean
• B. The distance from the median
• C. The variance around the mean
• D. The range of scores

Answer: (A)

Standard deviation measures how much scores vary around the mean. It represents the average distance of each score from the mean, after using squared deviations and then taking the square root to keep the units of the data. This makes it a precise, unit-friendly way to describe the spread of the data. It’s related to variance—the mean of squared deviations—but standard deviation is the square root of that value, which makes it easier to interpret. A small standard deviation means the data are clustered near the mean, while a large one indicates more spread. It doesn’t describe distance from the median or the overall range (which is simply max minus min).

Standard deviation measures how much scores vary around the mean. It represents the average distance of each score from the mean, after using squared deviations and then taking the square root to keep the units of the data. This makes it a precise, unit-friendly way to describe the spread of the data. It’s related to variance—the mean of squared deviations—but standard deviation is the square root of that value, which makes it easier to interpret. A small standard deviation means the data are clustered near the mean, while a large one indicates more spread. It doesn’t describe distance from the median or the overall range (which is simply max minus min).