Day 24 in Mat115

Today: Predicting the Future in an Uncertain World

• Return Exam 2
  • Add 7 to your score to get your grade.
  • An On-line key

• Collect problems 5.2, 6.1/2, rough drafts.

• Section 7.2:
  • The rules: (mostly encountered last time)

    • Probability:

      ratio of interesting events to all events

    • Relative Frequency: (empirical probabilities)

      ratio of successes ("interesting events" to total trials ("all events")

    • Law of Large Numbers:

      Relative Frequency tends to probability

      (This is the law that gives some order to randomness!)

    • Probability that it won't happen = 1- Probability that it will; or, alternatively,
    • Probability that it will happen = 1- Probability that it won't!
    • Maybe it's better to say this:

      (Probability that it will happen) + (Probability that it won't happen) = 1

  • The "games"
    • two sons problem:
      • Cards
      • Problem #8, p. 356