Q1. Which of the following statements about the variance of a normally distributed population is least accurate? A) The Chi-squared distribution is a symmetric distribution. B) The test of whether the population variance equals σ02 requires the use of a Chi-squared distributed test statistic, [(n − 1)s2] / σ02. C) A test of whether the variance of a normally distributed population is equal to some value σ02, the hypotheses are: H0: σ2 = σ02, versus Ha: σ2 ≠ σ02.
Q2. A test of the population variance is equal to a hypothesized value requires the use of a test statistic that is: A) F-distributed. B) Chi-squared distributed. C) t-distributed.
Q3. A munitions manufacturer claims that the standard deviation of the powder packed in its shotgun shells is 0.1% of the stated nominal amount of powder. A sport clay association has reviewed a sample of 51 shotgun shells and found a standard deviation of 0.12%. What is the Chi-squared value, and what are the critical values at a 95% confidence level, respectively? A) 72; 32.357 and 71.420. B) 72; 34.764 and 67.505. C) 70; 34.764 and 79.490.
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发表于 2009-1-13 16:14
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