“Standard deviation is the square of variance.”
Usage Entry 1462 / 1605 60-second read
Variance vs. Standard deviation
Average squared deviation from the mean versus the square root of variance.
The comparisoni
“Standard deviation is the SQUARE ROOT of variance. VARIANCE is the average squared deviation; SD is its square root, which is back in original units.”
The ruleii
¶
SD = √variance.
VARIANCE = average of (data - mean)². STANDARD DEVIATION = √variance — bringing the measure back into the original units. SD is more interpretable than variance for most purposes.
Memory aidiii
Remember it like this
SD is interpretable; variance is the math.