释义 |
Central Limit TheoremLet be a set of Independent random variates and each have an arbitrary probability distribution with Mean and a finite Variance . Then the normal form variate
 | (1) |
has a limiting distribution which is Normal (Gaussian)with Mean and Variance . If conversion to normal form is not performed, then thevariate
 | (2) |
is Normally Distributed with and . To provethis, consider the Inverse Fourier Transform of .
Now write | |  | | | (4) | so we haveNow expand
 | (6) |
so
since
Taking the Fourier Transform,
This is of the form
 | (11) |
where and . But, fromAbramowitz and Stegun (1972, p. 302, equation 7.4.6),
 | (12) |
Therefore,
But and , so
 | (14) |
The ``fuzzy'' central limit theorem says that data which are influenced by many small and unrelated random effects areapproximately Normally Distributed. See also Lindeberg Condition, Lindeberg-Feller Central Limit Theorem, Lyapunov Condition References
Abramowitz, M. and Stegun, C. A. (Eds.). Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, 9th printing. New York: Dover, 1972.Spiegel, M. R. Theory and Problems of Probability and Statistics. New York: McGraw-Hill, pp. 112-113, 1992. Zabell, S. L. ``Alan Turing and the Central Limit Theorem.'' Amer. Math. Monthly 102, 483-494, 1995.
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