Which statistic is described as the square root of the variance?

Which statistic is described as the square root of the variance?

• A. Standard Deviation
• B. Variance
• C. Sum of Squares
• D. Range

Answer: (A)

Dispersion is captured by variance and its companion, the standard deviation. The standard deviation is the square root of the variance, so it brings the measure back to the same units as the data and often makes interpretation much easier. Variance itself is the average of squared deviations from the mean, which means its units are squared, making it less intuitive. The sum of squares tallies up the squared deviations but isn’t a direct, standalone measure of spread. The range looks at the gap between the smallest and largest values, ignoring the overall shape of the distribution. Since we’re asked for the statistic that is the square root of the variance, the standard deviation is the correct choice.

Dispersion is captured by variance and its companion, the standard deviation. The standard deviation is the square root of the variance, so it brings the measure back to the same units as the data and often makes interpretation much easier. Variance itself is the average of squared deviations from the mean, which means its units are squared, making it less intuitive. The sum of squares tallies up the squared deviations but isn’t a direct, standalone measure of spread. The range looks at the gap between the smallest and largest values, ignoring the overall shape of the distribution. Since we’re asked for the statistic that is the square root of the variance, the standard deviation is the correct choice.