后三题都很简单,第一题我吃不准明天做给你~4:P=220/2000=0.11抽样极限误差为=P(1-P)/n的值开根号 =0.11*0.89/220 =0.02则区间为(0.11-0.02*1.96,0.11+0.02*1.96) =(0.0708,0.1492)
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