Khan Academy on a Stick

Population standard deviation

Variance and standard deviation

Range, variance and standard deviation as measures of dispersion
Variance of a population
Sample variance
Review and intuition why we divide by n-1 for the unbiased sample variance
Simulation showing bias in sample variance
Another simulation giving evidence that (n-1) gives us an unbiased estimate of variance
Simulation providing evidence that (n-1) gives us unbiased estimate
Population standard deviation
Sample standard deviation and bias
Statistics: Standard deviation
Exploring standard deviation 1 module
Statistics: Alternate variance formulas

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This collection was created November 2014.