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老师你好，请问这个答案怎么算出来的？我把数字带进去是3.5/根号下30=0.44，算不出答案里的数字，请问我哪里算出错了吗
NO.PZ2018122801000033 问题如下 If the meP/E of 30 stocks in a certain instrisector is 18 anthe sample stanrviation is 3.5, stanrerror of the meis CLOSEST to: 0.12 0.34 0.64 1.56 C is correct.考点 The CentrLimit Theorem解析 The stanrerror of the sample meis the stanrviation of the stribution of the sample means. Anit is calculateas:So, stanrerror of the me= s/ns/\sqrt ns/n = 3.5/303.5/\sqrt{30}3.5/30 = 0.64 老师好，还是有点混乱，分不清。想请问下如果这一句 “sample stanrviation is 3.5”，改成“sample mestanrviation is 3.5”的话，本题答案/标准误是不是直接就是3.5？
0.34 0.64 1.56 C is correct. 考点 The CentrLimit Theorem 解析 The stanrerror of the sample meis the stanrviation of the stribution of the sample means. Anit is calculateas: So, stanrerror of the me= s/ns/\sqrt ns/n = 3.5/303.5/\sqrt{30}3.5/30 = 0.64 n是30吗？为什么不是18？P/E是什么意思？
