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The standard deviation of n numbers $$x_{1}$$, $$x_{2}$$, $$x_{3}$$,......, $$x_{n}$$, with mean x is equal to $$\sqrt{\frac{s}{n}}$$, where S is the sum of the squared differences, $$(x_{i}- x)^{2}$$ for 1 ≤ i ≤ n.
If the standard deviation of the 4 numbers 140-a, 140, 160, and 160+a is 50, where a > 0, what is the value of a?
If the standard deviation of the 4 numbers 140-a, 140, 160, and 160+a is 50, where a > 0, what is the value of a?
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· 相关考点
5.2.9 标准差
5.2.9 标准差
以上解析由 考满分老师提供。
