中平均数的算术平方根,即为样本标准差. 小结 Evaluation only. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 计算例 2中两人射击环数的标准差,观察标准差的大小与总体稳定程度的关系. 由此看出,甲射击环数的标准差大,离散程度大,成绩不稳定;乙射击环数的标准差小,离散程度较小,成绩比甲稳定一些,可以选择乙参赛. 计算得: s 甲=1.73, s 乙=1.10. 例2 从甲、乙两名学生中选拔一人参加射击比赛,对他们的射击水平进行了测试,两个人在相同条件下各射击 10次, 命中的环数如下: 甲: 7 8 6 8 6 5 9 10 7 4 乙: 9 5 7 8 7 6 8 6 7 7 (2) 比较两人的成绩,然后决定选择哪一人参赛. Evaluation only. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd.
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