. As we might expect, we get the same values from applying the definition and from the parameter-based formulæ derived from it.
Computational Formulæ for the Mean and Variance
For some random variables, especially those following common named distributions, formulæ involving the parameters of the distribution can be derived to simplify computation of these values.
In the case of the Gamma distribution, the mean is αβ and the variance is . As we might expect, we get the same values from applying the definition and from the parameter-based formulæ derived from it.
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