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跟据一名西门费沙大学数学教授表示,目前国内使用的数学课本含有重大的错误,而可能会影响到国内学生的教育程度。 据Malgorzata Dubiel表示,她在去年审核国内的数学课本,而发现许多用词,定义和数学观念形容上的 ... [ 查看全文 ]
§ 发表于 2012-4-13
“在统计学上,‘平均值’和‘平均数’是相同的。但我们的课本并不是这样的解释。”
As a statistician, I think it is very necessary to point this out: in statistics, average and mean are different. an average can be thought as sample mean, but this does not mean the meaning of average is the same as the meaning of mean. Theoretical speaking, mean is referred as the true estimate of an expected value of underlying random variable, which is often estimated by sample mean. So, average is only a sample estimate of mean, but not the true value. The different between the estimate and the true value is often called a bias. To some extend, the textbook is right in this sense. |
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