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A game scores 1, 2 or 3 with chances 20%, 50% and 30%. What is the variance of the score?
A4.9
B0.7
C2.1
D0.49
Answer & Solution
Correct answer: D. 0.49
E(X squared) = 0.2 + 2.0 + 2.7 = 4.9 and the mean squared is 4.41, so the variance is 0.49.
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