Which measure is typically described as being in the same units as the data and used to describe dispersion?

Which measure is typically described as being in the same units as the data and used to describe dispersion?

• A. Standard deviation.
• B. Variance.
• C. Mean.
• D. Median.

Answer: (A)

Measuring how spread out data are is about dispersion. The standard deviation is described in the same units as the data themselves, which makes it easy to interpret what a typical deviation looks like in real terms. Since standard deviation is the square root of variance, its units match the data (for example, centimeters if heights are measured in cm). Variance, by contrast, is in squared units, which makes it harder to interpret directly. Mean and median tell you about the center of the data, not the spread. So the measure that matches the data's units and describes dispersion is the standard deviation.

Measuring how spread out data are is about dispersion. The standard deviation is described in the same units as the data themselves, which makes it easy to interpret what a typical deviation looks like in real terms. Since standard deviation is the square root of variance, its units match the data (for example, centimeters if heights are measured in cm). Variance, by contrast, is in squared units, which makes it harder to interpret directly. Mean and median tell you about the center of the data, not the spread. So the measure that matches the data's units and describes dispersion is the standard deviation.