SOLUTION: A true-false test consists of 50 questions. How many does a student have to get right to convince you that he is not merely guessing?

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Question 1197381: A true-false test consists of 50 questions. How many does a student have to get right to convince you that he is not merely guessing?
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

E%28X%29+=+np+=+50%280+.5%29+=+25 correct answers.
SD%28X%29+=sqrt%28+npq%29+=sqrt%28+50%2A+0.5+%2A0.5%29=+3.54+ correct answers.
Answers may vary.
In order be convincing, the student would have to answer at least 36 out of 50questions correctly, since 36 is approximately three standard deviations above the mean.
Answering fewer than 36 questions correctly could happen too often, simply due+to+chance.