答案和详解如下： Q6. What is the coefficient of variation for a distribution with a mean of 10 and a variance of 4? A) 20%. B) 40%. C) 25%. Correct answer is A) Coefficient of variation, CV = standard deviation / mean. The standard deviation is the square root of the variance, or 4½ = 2. So, CV = 2 / 10 = 20%. Q7. The historical return for each of a portfolio’s four positions is shown below. Using the population standard deviation, what is the coefficient of variation (CV) for these returns? Position Return A 17.0% B 12.2% C 3.9% D –8.4% A) 1.56. B) 3.12. C) 1.89. Correct answer is A) The coefficient of variation is equal to the standard deviation of returns divided by the mean return. Position Return (R – 6.175%)2
A 17.0% 117.18 B 12.2% 36.30 C 3.9% 5.18 D –8.4% 212.43 Mean 6.175% Sum = 371.09 Std. Dev. = (371.09 / 4)0.5 = 9.63 CV = 9.63 / 6.175 = 1.56 Q8. If the historical mean return on an investment is 2.0% and the standard deviation is 8.8%, what is the coefficient of variation (CV)? A) 4.40. B) 1.76. C) 6.80. Correct answer is A) The CV = the standard deviation of returns / mean return or 8.8% / 2.0% = 4.4. | 
发表于 2009-1-8 17:45
| 
