Standard Deviation Formula:
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Standard Deviation (SD) is a measure of how spread out numbers are in a dataset. It's the square root of the variance, which is the average of the squared differences from the mean.
The calculator uses the simple formula:
Where:
Explanation: Since variance is the average of squared differences, taking its square root returns the measure to the original units of the data.
Details: Standard deviation is widely used in statistics to measure variability or dispersion. It helps understand how much variation exists from the average value.
Tips: Simply enter the variance value (must be positive) and the calculator will compute the standard deviation.
Q1: What's the difference between SD and variance?
A: Variance is the average squared deviation from the mean, while SD is the square root of variance, expressed in the original units.
Q2: When would I need to calculate SD from variance?
A: When you have variance values from statistical analysis but need results in the original measurement units.
Q3: Can standard deviation be negative?
A: No, standard deviation is always non-negative because it's derived from a square root.
Q4: What does a high standard deviation indicate?
A: A high SD indicates that data points are spread out over a wider range of values.
Q5: Is this calculator suitable for population and sample variance?
A: Yes, the formula works for both population variance and sample variance.