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NO.PZ2015120604000130

问题如下：

We want to use z-statistic to construct confidence interval for a normally distribution. Assume the sample size is 100, sample mean is 15% and the standard deviation of sample is 25%. The significance level is supposed to be 10% , the confidence interval is :

选项：

- 10.88% to 19.13%.

10.88% to 19.13%.

10.88% to 20.57%.

解释：

B is correct.

In this case, we can know that the Confidence Interval=[Point Estimate +/- (reliability factor)*Standard error]=

$\bar{x} \pm z_{α / 2} \frac{σ}{\sqrt{n}} = 15 % \pm 1.65 \times \frac{25 %}{\sqrt{100}} = [10.88 %, 19.13 %]$

请解释题干以及该题涉及的原理所对应知识点

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星星_品职助教 · 2022年10月15日

同学你好，

本题考察计算置信区间，直接逐项代入公式即可。

如对公式有不了解的地方，可提出具体的问题。

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