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طب هذي الأسئله << أدري ثقلت

ممكن احد يفهمني ؟

Use the following to answer questions 29-31:
A multiple choice quiz consists of 6 questions, each with 5 possible answers. If a student guesses the answer
of each question, then
29. the probability of at least one correct answer is ...
A) 0.738 B) 0.607 C) 0.598 D) 0.709

30. the mean number of correct answers is ...
A) 0.83 B) 1.20 C) 0.875 D) 1.14
Page 4
31. the probability of guessing exactly two correct questions is ...
A) 0.246 B) 0.161 C) 0.227 D) 0.168

32. The mean of a normal probability distribution is 500 and the standard deviation is 10. About 95

percent of the observations lie between what two values?
A) 490 and 510 B) 480 and 520 C) 470 and 530 D) 450 and 550