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【单选题】
假设某商场顾客在单位时间内进入超市的人数服从正态分布。现以每十分一个时间单位对进入商场的顾客人数进行抽样调查,随机抽取30个时间单位,调查得到每十分钟平均进入某超市的女顾客和男顾客分别是为50.9人和21.9人,标准差分别是15.90人和5.97人。下列不正确的是( )。A.
样本中女顾客的比例是p= 50.9人/72.8人=69.92%
B.
本题中总体的变量x为顾客性别,它服从正态分布。
C.
本题中顾客总体的变量x可以是性别，它服从0-1分布。
D.
因为n=30,np=21＞5,n(1-p)=9＞5,为大样本，所以样本比例p近似服从正态分布。
E.
以95%的概率保证程度，估计进入该商场的女顾客比例的置信区间为
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