STATS 10 Lecture Notes - Lecture 5: Conditional Probability, Fair Coin, Empirical Probability
Document Summary
Data can change depending on who/when/how when collecting it. Least squares = least risky line that gives us good predictions. Streaks of 4, 3, and 5 are very common. It is more likely to see a streak of 3+ than not. Streak = same outcome several times in a row. Probabilities are defined by long run relative frequencies. Flip the coin x times then compute proportion/relative frequency of heads. Probabilities defined by updating prior beliefs according to bayes" mathematical rule. Prior = probability fair coin lands head is 1/2. Posterior = flip the coin and update beliefs based on results. Actual/true/definitive probability i. e. fair coin landing heads = 1/2. Long run relative frequencies based on what prob would be after infinite # of repetitions. Often want to estimate the theoretical probability bc we do not know it. Relative freq based on outcomes of an experiment/observation. Empirical and theoretical probabilities are different and do not equal.
