A random variable X takes the values 0, 1, and 2 with probabilities 0.2, 0.5, and 0.3, respectively. What is Var(X)?
Correct answer: A. 0.49
- A. 0.49
- B. 0.70
- C. 1.10
- D. 1.70
Explanation
The mean is E(X) = 1.1 and E(X²) = 1.7. Hence, Var(X) = E(X²) - [E(X)]² = 1.7 - 1.21 = 0.49.
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