11、Using Chebyshev's inequality, what is the proportion of observations from a population of 250 that must lie within three standard deviations of the mean, regardless of the shape of the distribution?

A. 67%

B. 75%

C. 89%

D. 99%

[此贴子已经被作者于2008-11-7 13:49:12编辑过]

11、Using Chebyshev's inequality, what is the proportion of observations from a population of 250 that must lie within three standard deviations of the mean, regardless of the shape of the distribution?

A. 67%

B. 75%

C. 89%

D. 99%

  
Correct answer = C

"Statistical Concepts and Market Returns," Richard A. Defusco, Dennis W. McLeavey, Jerald E. Pinto, and David E. Runkel
2008 Modular Level I, Vol. 1, pp. 289-291
Study Session 2-7-g
calculate and interpret the proportion of observations falling within a specified number of standard deviations of the mean, using Chebyshev's inequality
Chebyshev's inequality holds for any distribution, regardless of shape, and states that the proportion of observations located within k standard deviations of the mean is equal to 1 - 1 / k2. In this case, k = 3 and 1 - 1 / 9 = 0.89 or 89%. 

非常感谢

c

回

thanks