答案和详解如下： Q11. Which of the following is the CORRECT value of the correlation coefficient between aggregate revenue and advertising expenditure? A) 0.9500. B) 0.7780. C) 0.6053. Correct answer is B) The R2 = (SST - SSE)/SST = RSS/SST = (20,922.5 - 8,257.374) / 20,922.5 = 0.6053. The correlation coefficient is the square root of the R2 in a simple linear regression which is the square root of 0.6053 = 0.7780. Q12. Which of the following reports the CORRECT value and interpretation of the R2 for this regression? The R2 is: A) 0.3947 indicating that the variability of advertising expenditure explains about 39.47% of the variability of aggregate revenue. B) 0.6053 indicating that the variability of advertising expenditure explains about 60.53% of the variability in aggregate revenue. C) 0.6053 indicating that the variability of aggregate revenue explains about 60.53% of the variability in advertising expenditure. Correct answer is B) The R2 = (SST - SSE)/SST = (20,922.5 - 8,257.374) / 20,922.5 = 0.6053. The interpretation of this R2 is that 60.53% of the variation in aggregate revenue (Y) is explained by the variation in advertising expenditure (X). Q13. What is the y-intercept term, b0? A) 47.6712. B) 34.7400. C) 92.2840. Correct answer is A) The mean of the aggregate revenue (Y) is 3,645/10 = 364.50 and of the advertising expenditure (X) is 91.2/10 = 9.12. The y-intercept, b0 = MeanY – Slope × MeanX = 364.50 – 34.74 × 9.12 = 47.6712. Q14. What is the calculated F-statistic? A) 12.2700. B) 0.1250. C) 92.2840. Correct answer is A) The computed value of the F-Statistic = MSR/MSE = 12,665.12576 / 1,032.17178 = 12.27, where MSR and MSE are from the ANOVA table. | 
发表于 2009-1-7 13:45
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