Q26 of 108 Page 271

For the following probability distribution determine standard deviation of the random variable X.

We have,



We know that standard deviation of


Where, Var =E(X2)-[E(X)]2



∴VarX= [0.8+ 4.5+ 4.8]- [0.5+1.5+1.2]2


=10.1-(3.1)2


=10.1-9.61


=0.49


∴standard deviation of


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