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Homework Help: Need help with expected value

  1. May 10, 2010 #1
    1. The problem statement, all variables and given/known data

    Suppose that a particle starts at the origin of the real line and moves along the line in
    jumps of one unit. For each jump, the probability is p that the partical will jump one unit to the left and the probability is (1-p) that the particle will jump one unit to the right.
    Find the expected value of the position of the particle after n jumps.

    2. Relevant equations

    E(x)=[tex]\sumf(x)xdx[/tex] from -infinity to +infinity (continuous case)
    E(x)=[tex]\sumf(x)x[/tex] for all x (discrete case)

    3. The attempt at a solution

    p(0<p<1) =>jumps one unit left
    q=(1-p) =>jumps one unit right
  2. jcsd
  3. May 10, 2010 #2


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    Homework Helper

    Well seeing how there are only two outcomes with n trials, how are the positions of the particle distributed?
  4. May 10, 2010 #3
    im really not sure.
  5. May 10, 2010 #4


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    Homework Helper

    Which distributions do you know?
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