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Suppose we randomly draw $n$ balls from an urn with $m$ red balls and $N-m$ white balls. Let $X$ be the number of red balls in our sample. Then $X$ has a hypergeometric distribution with pmf $p(x)=P(X=x)= {_mC_x} \times _{N-m}C_{n-x}/_NC_n$. What is the $E(X)$ and $\operatorname{Var}(X)$ ?

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