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 
26