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QUESTION

A discrete random variable can take the values $1,2$ and 3 with
probabilities $\ds\frac{1}{2},\ \frac{1}{4}$ and $\ds\frac{1}{4}$
respectively. Obtain the mean.

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ANSWER

Mean=$\ds\frac{1}{2}(1)+\frac{1}{4}(2)+\frac{1}{4}(3)
=\frac{1}{2}+\frac{1}{2}+\frac{3}{4}=\frac{7}{4}$




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