How can you measure how spread out numbers are?
Variance
How can you measure how spread out numbers are?
Imagine you have a basket of apples. Some baskets have apples clumped together, while others have apples scattered everywhere. You want to know which basket has apples spread out the most.
Think of the apples in the basket as a set of numbers. The more spread out they are, the higher the variance. Variance tells us how much the apples (numbers) differ from the average number of apples per basket.
Example
If one basket has 10 apples and another has 2 apples, the variance helps us understand which basket's apple distribution is more spread out.
Remember this
Variance measures how much the numbers (apples) differ from their average, showing the spread of the distribution.
Text adapted from Wikipedia, licensed under CC BY-SA 4.0.
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Algorithms for calculating variance
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Standard deviation
Standard deviation (σ) is the square root of variance
Monte Carlo method
Delta method approximates variance of g(X) ≈ [g'(μ)]² Var(X)
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Gaussian function
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