作业帮一条抽样的英文的题目Eggs sold in a supermarket are packed in boxes of 12.For each egg,the probability that it is cracked is 0.05,independently of all other eggs.A random sample of n boxes is selected and the variance of the sample mean numb
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一条抽样的英文的题目Eggs sold in a supermarket are packed in boxes of 12.For each egg,the probability that it is cracked is 0.05,independently of all other eggs.A random sample of n boxes is selected and the variance of the sample mean numb
一条抽样的英文的题目
Eggs sold in a supermarket are packed in boxes of 12.For each egg,the probability that it is cracked is 0.05,independently of all other eggs.A random sample of n boxes is selected and the variance of the sample mean number of cracked eggs in a box is 0.019.Find the values of n.
鸡蛋12个一盒，每个鸡蛋破掉的概率是0.05且相对独立。
现在有n盒鸡蛋，破掉的鸡蛋数的样本方差是0.019，求n的值。
一条抽样的英文的题目Eggs sold in a supermarket are packed in boxes of 12.For each egg,the probability that it is cracked is 0.05,independently of all other eggs.A random sample of n boxes is selected and the variance of the sample mean numb
这道题要用公式解
设X为破掉的蛋数,则X服从二项分布,实验次数是12n,成功率为0.05
则方差为 12n*0.05*0.95
12n*0.05*0.95＝0.019
得n=1/30
虽然不合实际,不过是这么解了