答案和详解如下： Q14. Find the mean, median, and mode, respectively, of the following data: 3, 3, 5, 8, 9, 13, 17 A) 8; 8.28; 3. B) 8.28; 8; 3. C) 3; 8.28; 8. Correct answer is B) Mean = (3 + 3 + 5 + 8 + 9 + 13 + 17) / 7 = 8.28; Median = middle of distribution = 8 (middle number); Mode = most frequent = 3. Q15. An investor has a $15,000 portfolio consisting of $10,000 in stock A with an expected return of 20% and $5,000 in stock B with an expected return of 10%. What is the investor’s expected return on the portfolio? A) 16.7%. B) 12.2%. C) 7.9%. Correct answer is A) Find the weighted mean where the weights equal the proportion of $15,000. [(10,000 / 15,000) × 0.20] + [(5,000 / 15,000 × 0.10] = 16.7%. Q16. An investor has a portfolio with 10% cash, 30% bonds, and 60% stock. If last year’s return on cash was 2.0%, the return on bonds was 9.5%, and the return on stock was 25%, what was the return on the investor’s portfolio? A) 36.50%. B) 22.30%. C) 18.05%. Correct answer is C) Find the weighted mean of the returns. (0.10 × 0.02) + (0.30 × 0.095) + (0.60 × 0.25) = 18.05% Q17. Which of the following statements about a normal distribution is least accurate? A) Approximately 68% of the observations lie within +/- 1 standard deviation of the mean. B) The mean and variance completely define a normal distribution. C) A normal distribution has excess kurtosis of three. Correct answer is C) Even though normal curves have different sizes, they all have identical shape characteristics. The kurtosis for all normal distributions is three; an excess kurtosis of three would indicate a leptokurtic distribution. Both remaining choices are true. | 
发表于 2009-1-6 11:13
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