<PRE><B>Question 404133</B>
In a multiple choice test, each question has four options, students get 10 points for each correct answer, lose four points for each incorrect answer, and receive no points for unanswered question. 
the student does not know the answer for one question, is it to her advantage or disadvantage to guess an answer.
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Determine the expected value:
Random values: 10, -4, 0
Probabilities: (1/4), (3/4), her option
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E(x) = (1/4)(10)+(3/4)(-4) = (10-12)/4 = -1/2 point
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It would be better to not answer the question.
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Cheers,
Stan H.</PRE>