3975

答案和详解如下：

19、Correct answer is 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. 268-272

Study Session 2-7-d

define, calculate, and interpret measures of central tendency, including the population mean, sample mean, arithmetic mean, weighted average or mean (including a portfolio return viewed as a weighted mean), geometric mean, harmonic mean, median, and mode

Unless all the observations in a dataset have the same value, the harmonic mean is less than the geometric mean, and the geometric mean is less than the arithmetic mean.