SOLUTION: 7. In a multiple-choice test, each question has four options. Students will get 4 points for each correct answer; lose 1 point for each incorrect answer; and receive no points for

Algebra ->  Probability-and-statistics -> SOLUTION: 7. In a multiple-choice test, each question has four options. Students will get 4 points for each correct answer; lose 1 point for each incorrect answer; and receive no points for       Log On


   

Question 549938: 7. In a multiple-choice test, each question has four options. Students will get 4 points for each correct answer; lose 1 point for each incorrect answer; and receive no points for unanswered questions. A student does not know the correct answer for one question. Is it to her advantage or disadvantage to guess an answer? Show your calculations for expected value

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In a multiple-choice test, each question has four options.
p(correct) = 1/4 ; p(incorrect) = 3/4
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Students will get 4 points for each correct answer; lose 1 point for each incorrect answer; and receive no points for unanswered questions.
Random "gain" values: 4:::-1:::0
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A student does not know the correct answer for one question. Is it to her advantage or disadvantage to guess an answer? Show your calculations for expected value
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E(x) = (1/4)4 + (3/4)(-1) + 0 = 1/4
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He should answer every question.
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Cheers,
Stan H.
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