[!!!急]數學_Probility_4
2009-06-03 4:38 am
In a multiple-choice test, each question has four options among which only one is correct. If there are 20 questions, find the expected number of correct answers if you choose all the answers randomly.
回答 (1)
2009-06-03 5:54 am
✔ 最佳答案
用Binomial distribution計B ( n=20, p=1/4 )
expected number = np = 20 x 1/4 = 5
收錄日期: 2021-04-13 16:38:53
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https://hk.answers.yahoo.com/question/index?qid=20090602000051KK01529