alleryFor a discrete random variable X with values 0, 1, 2 and probabilities 0.3, 0.5, 0.2 respectively, the mean E(X) is:
A$0.5$
B$1.0$
C$1.2$
D$0.9$
Answer & Solution
Correct answer: D. $0.9$
We have E(X) = Σ x × P(x).
That is E(X) = 0×0.3 + 1×0.5 + 2×0.2.
That is E(X) = 0 + 0.5 + 0.4.
So E(X) = 0.9.
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