Question

how do standard deviation and variance differ?
o a. variance in a parameter and standard deviation is a statistic
o b. standard deviation is the average deviation of scores from the mean but variance is the distance of scores from the mean
o c. variance is given in squared units but standard deviation is given in regular score units
o d. variance is the average deviation of scores from the mean but standard deviation is the distance of scores from the mean
o e. standard deviation is given in squared units but variance is given in regular score units

Explanation:

Variance is calculated as the average of the squared deviations from the mean, so it has squared units of the original data. Standard deviation is the square root of the variance, which converts it back to the original, regular units of the data. Option a is incorrect because both can be parameters (for populations) or statistics (for samples). Options b and d misdefine the measures: variance is the average of squared deviations, not average deviation, and standard deviation is the square root of that average, not raw distance. Option e reverses the unit relationship.

Answer:

C. variance is given in squared units but standard deviation is given in regular score units