Friday, May 10, 2013

Expected Value Exercise 8




Expected Value Exercise 8




1.     Consider a lottery with three possible outcomes:
    $125 will be received with probability 0.2
    $100 will be received with probability 0.3
    $50 will be received with probability 0.5

a.   What is the expected value of the lottery?

b.   What is the variance of the outcomes?

c.   What would a risk-neutral person pay to play the lottery?



6 comments:

  1. a. E(x)= 0.2(125) + 0.3(100) + 0.5 (50)
    25+30+25
    =80

    b. variance = 0.2[(125-80)square] + 0.3[(100-80)square] + 0.25 [(50-80)square]
    =405 + 120 +450
    =975

    c. we have to find the standard deviation to know how big is the risk. take a root from variance 31.22. yes, he would. because there's a risk neutral indifferent between uncertain and certain payoffs with the same expected value.

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  2. 3 possible outcomes from a lottery
    - 0.2 will received $125
    - 0.3 will received $100
    - 0.5 will received $50

    a. Expected Value : (1st Pr)(1stprize) + (2nd Pr)(2ndprize)+(3rdPr)(3rdprize)
    EV : (0.2)($125) + (0.3)($100) + (0.5)($50) = 25 + 30 + 25 = $80
    so, it means from the probability of the lottery returns $80

    b. the Variance or S2 (S square)
    S2 : (0.2) ($125-80)2 + (0.3) ($100-80)2 + (0.5) ($50-80)2 = $975
    the variance describing how far the numbers lie from the expected value which is $975

    c. a risk-neutral person would buy the lottery, and naturally would pay the $80 because risk-neutral is being indiffirent(ignore) between certain and uncertain so no need to calculate the risk.

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  3. a. EV= (125x0.2)+(100x0.3)+(50x0.5)= 80
    b. variance= 0.2(125-80)2+0.3(100-80)2+0.5(50-80)2=975
    c. as we know that a risk neutral person is indifferent between certain income and uncertain income, so this person doesnt care about their income which related to their risk.

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  4. a. E(v)= 0.2(125)+0.3(100)+0.5(50)
    =$80
    b. V= 0.2(125-80)2+0.3(100-80)2+0.5(50-80)2
    =$975
    c. a risk neutral person would pay the $80 as the expected value

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  5. a. E(v)= (0.2)(125)+(0.3)(100)+(0.5)(50)
    = 25 + 30 + 25
    = 80
    b. V = (0.2)(125-80)(2) + (0.3)(100-80)(2)+(0.5)(50-80)(2)
    = 975
    c. the risk neutral person is indifferent between certain income and an uncertain income. so this person will pay the lottery $80 as the result of expected value

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  6. ANSWER:

    a.
    The expected value, EV, of the lottery is equal to the sum of the returns weighted by their probabilities:
    EV = (0.2)($125)  (0.3)($100)  (0.5)($50) = $80.

    b.
    The variance is the sum of the squared deviations from the mean, $80, weighted by their probabilities:
    Variance = (0.2)(125  80)2  (0.3)(100  80)2  (0.5)(50  80)2 = $975.

    c.
    A risk-neutral person would pay the expected value of the lottery: $80.

    ReplyDelete