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Chemical Applications of Statistical Analyses
Random Error in Measurements
Description
Random error in measurements comes from uncontrollable variables that affect data from one trial to the next. These variables can include changes in the environment, imperfections in an instrument, or the natural variation of the thing being measured. Because the direction and size of the error can change from one measuremen...
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Transcript
不定或随机误差源于连续测量中多个无法控制的变量。
由于这些误差既无法预测也无法估算,因此永远无法消除。有时甚至难以识别出具体的误差来源。 以仪器中电噪声引起的随机误差为例,其波动可向正负两个方向发生,且幅度各不相同。
由于这些随机变化,不定误差呈现离散分布。然而,对于大量数据集,概率的数学定律有助于通过平均值或中位数找到最可能的结果。
当绘制带有随机误差的数据时,数值会在最常出现的中心值两侧分布。随着数值偏离中心值而变大或变小,其出现的频率逐渐降低。这种分布图称为高斯曲线。
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