Q6. A sample of size n = 25 is selected from a normal population. This sample has a mean of 15 and a sample variance of 4. What is the standard error of the sample mean? A) 0.4. B) 2.0. C) 0.8.
Q7. Melissa Cyprus, CFA, is conducting an analysis of inventory management practices in the retail industry. She assumes the population cross-sectional standard deviation of inventory turnover ratios is 20. How large a random sample should she gather in order to ensure a standard error of the sample mean of 4? A) 25. B) 20. C) 80.
Q8. From a population with a known standard deviation of 15, a sample of 25 observations is taken. Calculate the standard error of the sample mean.
A) 0.60. B) 3.00. C) 1.67.
Q9. The mean return of Bartlett Co. is 3% and the standard deviation is 6% based on 20 monthly returns. What is the respective standard error of the sample and the confidence interval of a two tailed z-test with a 5% level of significance? A) 1.34; 0.37 to 5.629. B) 2.00; 0.37 to 5.629. C) 1.34; −0.66 to 4.589.
Q10. Joseph Lu calculated the average return on equity for a sample of 64 companies. The sample average is 0.14 and the sample standard deviation is 0.16. The standard error of the mean is closest to: A) 0.1600. B) 0.0025. C) 0.0200.
| 
发表于 2009-1-9 10:58
| 
