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I am an instructor at a high school and just gave a fifty item multiple choice exam (a,b,c,d). Five students who sit together at a table got the same 8 of the 50 questions wrong. What is the probability of that happening? I want to be able to support the fact that I believe they cheated. Thanks!
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\n" ); document.write( "The probability I give the same answer as you on one question is 1/2
\n" ); document.write( "The probability that 6 others give the same answer is (1/2)^6
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\n" ); document.write( "The probability 8 of us give the same answer is (1/2)^7
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\n" ); document.write( "The probability that happens on 8 questions is (1/2)^7^8 = (1/2)^56
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\n" ); document.write( "BUT, if we assume the 8 questions could hardly be answered incorrectly
\n" ); document.write( "by anyone taking your class, the probability does not change, but the
\n" ); document.write( "reality of the situation would force us to reasses our suspicion.
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\n" ); document.write( "In other words the theoretical probability does not always tell the
\n" ); document.write( "whole story about events. It only tells us something about RANDOM
\n" ); document.write( "events.
\n" ); document.write( "Question: What is the probability your car will follow some particular
\n" ); document.write( "car at a particular red light tomorrow morning? Small, right?
\n" ); document.write( "But what is the probability you will follow some car? Hugh, right?
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\n" ); document.write( "Recommend: Look beyond the probabilities.
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "