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AP EAMCET202018 Sep 2020Morning ShiftMathematicsProbabilityActual

Suppose (X ) has the following probability mass function (P(X=0)=0.2, P(X=1)=0.5 ), (P(X=2)=0.3 ). What (E [X^2 ]= ) ?

Options

  1. A2.89
  2. B1.70
  3. C1.10
  4. D1.21

Correct answer

B. 1.70

Step-by-step solution

Given probability distribution is ( array c|c|c|c X & 0 & 1 & 2 P(X) & 0.2 & 0.5 & 0.3 array ) ( aligned E (X^2 ) & = p_i x_i^2 p_i = ((0.2) 0^2 )+ (0.5 1^2 )+ (0.3 2^2 ) 0.2+0.5+0.3 & = 0.5+1.2 1 =1.7 aligned )

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