In Probability and Statistics, the standard deviation of a statistical population or data set is a measure of how much variation or dispersion exists from its average value. It is defined as the square root of the variance.
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Denominator to calculate standard deviation
I've just read something about calculating sample standard deviation. Some explanations say that it is because of degree of freedom. With a constraint that the mean should be zero, we do actually have ...
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How to calculate the expected value $E(XY)$ with known $E(X)$, $E(Y)$ and $\sigma_{i}$?
I am trying to understand the value of $\bar{x_{1} x_{2}}+E(x_{1} x_{2})$. For all $i$, $E(x_{i})$ and $\sigma_{i}$ are given. Wikipedia gives the joint probability density function:
$E(XY) = \int ...
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Calculate standard deviation of merged sets with limited information (full details inside)
I have:
A1: {3, 5, 6} and A2: {3, 4, 6, 8}
Avg A1: 4.(6)
Std.Deviation A1: 1.247
Avg A2: 5.25
Std. Deviation A2: 1.92
Merging A1 and A2, we get
A12: {3, 3, 4, 5, 6, 6, 8}
Avg A12: 5
Std. ...
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2answers
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Calculating the “jaggedness” of a distribution
I'm sure "jaggedness" isn't the right term to use here, so please correct me. I'm trying to quantify how jagged a distribution is. For example, this is moderately jagged:
distribution #1
This is ...
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vote
3answers
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Chebyshev's theorem
OK, so here's the question (not my homework - which is line segments -_-)
According to Chebyshev's theorem, how
many standard deviations from the mean
would make up the central 60% of
...
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votes
1answer
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Sample Standard Deviation vs. Population Standard Deviation
I have an HP 50g graphing calculator and I am using it to calculate the standard deviation of some data. In the statistics calculation there is a type which can have two values:
Sample
Population
I ...
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2answers
667 views
Is it possible to calculate the standard deviation without the samples?
Imagine I had two sets of samples. The only information I have about them is their
Size
Average
Standard deviation
Is it possible to calculate the standard deviation of a third set that is ...
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1answer
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Max of multistep Gaussian walk vs max of multiple single-step Gaussian walks
Is there a relation between the max of a Gaussian random walk of 10
steps vs the max of 10 Gaussian random walks? Specifics (in
Mathematica notation):
...
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votes
4answers
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Motivation behind standard deviation?
Let's take the numbers 0-10. Their mean is 5, and the individual deviations from 5 are
-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5
And so the average (magnitude of) ...
