A random variable X has the distribution law as given below:

The variance of the distribution is:
Explanation
Solution
Step 1: Calculate the Mean (Expected Value), E(X)
E(X)=∑xiP(xi)
E(X)=(1×0.3)+(2×0.4)+(3×0.3)
E(X)=0.3+0.8+0.9
E(X)=2.0
Step 2: Calculate E(X2)
E(X2)=∑xi2P(xi)
E(X2)=(12×0.3)+(22×0.4)+(32×0.3)
E(X2)=(1×0.3)+(4×0.4)+(9×0.3)
E(X2)=0.3+1.6+2.7
E(X2)=4.6
Step 3: Calculate the Variance, Var(X)
Var(X)=E(X2)−[E(X)]2
Var(X)=4.6−(2.0)2
Var(X)=4.6−4.0
Var(X)=0.6
Final Answer:
The variance of the distribution is 0.6, which corresponds to Option 2.
Explanation
Solution
Step 1: Calculate the Mean (Expected Value), E(X)
E(X)=∑xiP(xi)
E(X)=(1×0.3)+(2×0.4)+(3×0.3)
E(X)=0.3+0.8+0.9
E(X)=2.0
Step 2: Calculate E(X2)
E(X2)=∑xi2P(xi)
E(X2)=(12×0.3)+(22×0.4)+(32×0.3)
E(X2)=(1×0.3)+(4×0.4)+(9×0.3)
E(X2)=0.3+1.6+2.7
E(X2)=4.6
Step 3: Calculate the Variance, Var(X)
Var(X)=E(X2)−[E(X)]2
Var(X)=4.6−(2.0)2
Var(X)=4.6−4.0
Var(X)=0.6
Final Answer:
The variance of the distribution is 0.6, which corresponds to Option 2.