MCQ
Find the expectation of a random variable X.
$X$$0$$1$$2$$3$
$f(X)$$\frac{1}{6}$$\frac{2}{6}$$\frac{2}{6}$$\frac{1}{6}$
  • A
    0.5
  • 1.5
  • C
    2.5
  • D
    3.5

Answer

Correct option: B.
1.5
(B) 1.5
Explanation:
$E(X)=0\left(\frac{1}{6}\right)+1\left(\frac{2}{6}\right)+2\left(\frac{2}{6}\right)+3\left(\frac{1}{6}\right)$
$=0+\frac{2}{6}+\frac{4}{6}+\frac{3}{6}$
$=\frac{9}{6}=\frac{3}{2}=1.5$

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