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For the following probability distribution :
The value of $E(X^2)-[E(X)]^2$ |
1 3 10 7 |
1 |
The correct answer is Option (1) → 1 $E(X)=EX_iP(X_i)$ $=\frac{1}{10}+\frac{2}{5}+\frac{9}{10}+\frac{8}{5}$ $=\frac{30}{10}=3$ $E(X^2)=EX_i^2P(X_i)$ $=\frac{1}{10}+\frac{4}{5}+\frac{27}{10}+\frac{32}{5}$ $=\frac{100}{10}=10$ $E(X^2)-(E(X))^2=10-3^2=1$ |
