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If X be a random variable taking values ...

If X be a random variable taking values `x_(1),x_(2),x_(3),….,x_(n)` with probabilities `P_(1),P_(2),P_(3)`,…..`P_(n)`, respectively. Then, Var (x) is equal to …….. .

Text Solution

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Var (X) = `E(X)^(2)-[E(X)]^(2)`
=`underset(i=1)overset(n)SigmaX^(2)P(X)-"["underset(i=1)overset(n)SigmaXP(X)"]"^(2)`
`=SigmaP_(i)x_(i)^(2)-(SigmaP_(i)x i)^(2)`
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