In a multiple-choice test, each question has four options. Students will get 5 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.
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c=correct, i= incorrect, q= # of questions p= positive points n=negative points t=total points earned
1/4t=c, c•5= p
3/4t=i i=n
p-n=t
lets say t=20
1/4•20=c
5=c
5•5=25, p=25
3/4•20=i
15=i
15=n
25-15=10
it is an advantage to guess
1/4t=c, c•5= p
3/4t=i i=n
p-n=t
lets say t=20
1/4•20=c
5=c
5•5=25, p=25
3/4•20=i
15=i
15=n
25-15=10
it is an advantage to guess
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each question has four options that's why there is a possibility to make right choice is 25%. but students will get 5 points for each correct answer; lose 1 point for each incorrect answer.
so in 4 questions if you give 1 right answer then your points will be = (5 * 1) - (1 * 3) = 2
so students should answer all the questions and it will be advantageous then giving no answer.
so in 4 questions if you give 1 right answer then your points will be = (5 * 1) - (1 * 3) = 2
so students should answer all the questions and it will be advantageous then giving no answer.
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If you honestly don't kno an don hav a clue then ur chances are 25% per choice unless u jus kno one answer choice us too ridiculous. So it comes down to how much of a gamble u are willing to take. Do u want to chance getting 1 point wrong for the chance at 5 or do u jus want to play it safe an not answer an get 0 marked on or off