微信扫一扫
实时资讯全掌握
|
Abby Ness is an analyst for a firm that specializes in evaluating firms involved in mineral extraction. Ness believes that the earnings of copper extracting firms are more volatile than those of bauxite extraction firms. In order to test this, Ness examines the volatility of returns for 31 copper firms and 25 bauxite firms. The standard deviation of earnings for copper firms was $2.69, while the standard deviation of earnings for bauxite firms was $2.92. Ness’s Null Hypothesis is σ12 = σ22. Based on the samples, can we reject the null hypothesis at a 95% confidence level using an F-statistic and why? Null is: A. rejected. The F-value exceeds the critical value by 0.71. B. not rejected. The critical value exceeds the F-value by 0.71. C. rejected. The F-value exceeds the critical value by 0.849. D. not rejected. The critical value exceeds the F-value by 0.194. |