Pierre Simon Laplace, Inverse Probability, Central Limit Theorem, Probability, Deep Dives.
n tickets at random from the urn. Let the discrete random variable X_bar_n denote the number of black tickets in your random sample. Thus, the observed proportion of black tickets in the sample is X_bar_n/n. X_bar_n follows the binomial probability distribution with parameters n and p, i.e. X_bar_n