来自：FRM > 一级 > 【2021.11】FRM一级机考模拟考试 2024-01-17 16:09
老师，这题怎么做？
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71天前
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Ben 2024-01-18 10:11
致精进的你:
同学你好，这道题题干不完整，完整信息如下： A statistician wants to investigate two samples were drawn from a normally distributed population. The first sample, the mean was $55, and the standard deviation was $6. The second sample, the mean was $58, and the standard deviation was $8. The first sample consists of 16 observations, and the second sample consists of 25 observations. (Note: In the following Questions, the subscripts “A” and “B” indicate the first and second sample, respectively.) Adjust the significant level from 1 percent to 5 percent and a hypothesis test structure of H0: σA ≤ $5 versus Hₐ:σA > $5. At a 1 percent level of significance, the null hypothesis: 解析：解析： 卡方检验用于检验单个方差的假设检验，所以卡方检验是单尾检验，如果 X^2> α= 0.01, df = 15 时的卡方关键值，则判定是拒绝 H0。 x2n-1= (n-1)S^2/σ20=15*36/25=21.6 右尾临界卡方值为 24.996., 由于 X^2 = 21.6＜ 24.996，H0 不能被拒绝。
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追问12024-01-18 16:45
右尾临界卡方值为 24.996，是怎么知道的？
回答2024-01-19 09:05
这个需要查卡方分布表，考试的时候会直接给出的，因为考试不提供卡方分布表。
