Convergence, Probability, Cumulative Distribution, Statistics, Editors Pick.
will E(W) be zero? |X_k — X| being the absolute value will never be negative. Hence, the only two ways in which the E(|X_k — X|) will be zero is if: For every pair of observed values of X_k and X, |X_k — X| is zero, OR The probability of observing any non-zero difference in values is zero. Either