we will use set theory for the mathematical model of events.outcomes of an experiment are elements of some sample space S,and each event is a subset of S.two events both occur if the outcome is in the intersection of two sets.at least one of a collection of events occurs if the outcome is the union of the sets.two events can not both occur if the sets are disjoint.an event fails to occur if the outcome is the complement of the set.the empty set stands for every event that cannot possibly occur.the collection of events is assumed to contain the sample space,the complement of each event,and the union of each countable collection of events. (查看原文)
a box contains 100 balls,of which r are red.suppose that the balls are drawn from the box one at a time,at random,without replacement.determine(a) the probability that the first ball drawn will be red;(b)the probability that the 50th ball drawn will be red;(c)the prbability that the last ball drawn will be red. (查看原文)
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Pearson2011版
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Pearson2011版
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Addison Wesley2001版
1 有用 钱德勒·宾 2020-06-28 12:50:54
连个评分都没有可还行。。。看在我们老师的面子上来个五分 但我知道我看不懂(눈_눈)
0 有用 peach in July 2013-09-10 18:30:32
伤不起真的伤不起……考试还用英文……
1 有用 钱德勒·宾 2020-06-28 12:50:54
连个评分都没有可还行。。。看在我们老师的面子上来个五分 但我知道我看不懂(눈_눈)
0 有用 peach in July 2013-09-10 18:30:32
伤不起真的伤不起……考试还用英文……