题干

某电视台在一次对收看文艺节目和新闻节目观众的抽样调查中,随机抽取了100名电视观众,相关的数据如表所示:


(Ⅰ)用分层抽样方法在收看新闻节目的观众中随机抽取5名,大于40岁的观众应该抽取几名?

(Ⅱ)在上述抽取的5名观众中任取2名,求恰有1名观众的年龄为20至40岁的概率.

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答案(点此获取答案解析)

解:(I)在100名电视观众中,收看新闻的观众共有45人,其中20至40岁的观众有18人,大于40岁的观众共有27人.
故按分层抽样方法,在应在大于40岁的观众中中抽取45
5
×27=3
人.

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