
 Mean, Variance and Distributions 
  In addition, it is assumed that the values are drawn from a sample distribution taken from a larger population., and that the variance and standard deviation of the population are to be estimated. 
  where p(x) is proportional to the probability that the actual value will equal x; ev and sd stand for the expected value and standard deviation, respectively, of the distribution, and nd is the deviation of x from ev in standard deviation units. 
  For example, the expected shortfall is the expected value of the shortfall, whether there is one or not. 
 www.stanford.edu /~wfsharpe/mia/rr/mia_rr1.htm (3358 words) 
