Subtopic: Mean, median, mode and standard deviation
Question Statement:
A statistical measure of the variability of a distribution around its mean is referred to as
Options:
(A) coefficient of determination
(B) standard error
(C) coefficient of variation
(D) standard deviation
Official Answer Key:
D
Step-by-Step Solution & Explanation
Standard deviation is, by definition, the square root of the average squared deviation of observations from the mean — it directly measures spread/variability about the mean in the same units as the data. Coefficient of variation (C) normalizes the standard deviation by the mean (a relative, unit-less measure, useful for comparing variability across datasets), coefficient of determination (A) (R²) measures goodness of fit in regression, and standard error (B) measures the precision of a sample statistic (e.g. the mean) as an estimator, not variability of the raw distribution itself.
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