Standard Deviation Formula:
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Standard Deviation is a measure of how spread out numbers are in a dataset. It quantifies the amount of variation or dispersion from the average (mean) value.
The calculator uses the standard deviation formula:
Where:
Explanation: The formula calculates how far each value is from the mean, squares these differences, averages them, and then takes the square root.
Details: Standard deviation is crucial in statistics for understanding data variability. It's used in finance, research, quality control, and many other fields to measure risk, consistency, and reliability.
Tips: Enter your numerical data points separated by commas (e.g., 5, 10, 15, 20). The calculator will compute the mean, variance, and standard deviation.
Q1: What's the difference between population and sample standard deviation?
A: Population SD divides by N (total items), while sample SD divides by N-1. This calculator provides population SD.
Q2: What does a high standard deviation indicate?
A: High SD means data points are spread out over a wider range of values, showing more variability.
Q3: What are the units of standard deviation?
A: SD has the same units as the original data points (e.g., cm for height data, dollars for price data).
Q4: How is standard deviation related to variance?
A: Variance is the square of standard deviation. Both measure spread but in different units.
Q5: When should I use standard deviation?
A: Use it when you need to understand how much variation exists in your data, compare different datasets, or assess data reliability.