Recall from Chapter 4 & 5 that the cumulative distribution function (CDF) is given by F(x) = P(X lessthanorequalto x)= integral^x_infinity f(t)dt or Sigma_x_i lessthanorequalto x(x_i) for a continuous and discrete RV, respectively. Here we examine the sample version of the cumulative distribution function, namely the empirical distribution function. When it is not suitable to assume a specific distributional assumption for F, we may use the empirical distribution function as an estimate of the underlying distribution. The empirical distribution is based on the order statistics (Chapter 6). For a random sample of size n, the order statistics are defined as X_(1) lessthanorequalto X_(2)