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Just asking out of curiosity. A homework question asked for the mean and variance of a distribution, and they turned out to be equal. It's not obvious to me that the distribution in question is poisson though.

Reylined
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1 Answers1

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take a normal with mean and variance 1. I.e. a standard normal plus 1.

Mark Joshi
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  • Oh true, didn't think about it like that. But to take it one step further, is Poisson the only one where you do not have to specify the parameter? – Reylined Dec 01 '16 at 05:05
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    I don't the question is really mathematically answerable -- you could always define a sub-class of a more general family which restricts it to cases where mean and variance are equal. – Mark Joshi Dec 02 '16 at 00:09