kmbsuperbus
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註冊 30/3/2011
來自 Racecourse
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發表於 13/4/2012 12:29 AM
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先感謝各位的幫忙, thank you!
整多條, 呢條d & e 5識, 幫幫忙, thank you.
One more question on probability
The grades of 100 students in Chinese and English are summarized:
Chinese
A B C Total
English A 12 5 15 32
B 12 10 15 37
C 6 15 10 31
Total 30 30 40 100
(a) Find the probability of a randomly selected student getting an A in both Chinese and English? 2 decimal places.
(b) Find the probability of a randomly selected student getting an A in either Chinese or English? 2 decimal places.
(c) Given that a randomly selected student getting a C in Chinese, find the probability that he or she got an A in English? 2 decimal places.
(d) If 2 students are selected randomly from these 100 students without replacement, find the probability that both of them got an A in at least one subject? 4 decimal places.
(e) If 3 students are selected randomly from these 100 students with replacement, find the probability that all of them have better grades in Chinese? 4 decimal places.
[ 本帖最後由 kmbsuperbus 於 13/4/2012 12:31 AM 編輯 ]
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