SOLUTION: A multiple-choice test consists of 38 questions with possible answers of a, b, c, d. Estimate the probability that with random guessing, the number of correct answers is at least 1
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Question 1178490: A multiple-choice test consists of 38 questions with possible answers of a, b, c, d. Estimate the probability that with random guessing, the number of correct answers is at least 13. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! mean is np=38*0.25=9.5
variance is np(1-p)=9.5*0.75=7.125
sd is sqrt(V)=2.67
at least 13 would be z > (12.5-9.5)/2.67, using the continuity correction factor, or z>1.124 with probability of 0.1306 rounding at the end.
