Probability&randomness

Randomness

not a property of a phenomenon. depends amongst others of prior knowledge, observation method, and a scale at which the phenomenon is considered.

• 행위를 여러번 했을 때, 무작위성은 일종의 성공 비율을 갖게 됨
  
  

  Probability

tree diagram and sampel space(표본공간)

disjoint(분리) mutually exclusive(상호배타적) jointly(공동)

Bayes’ law

check!

• disjoint: 서로소집합(교집합X)
• independent: 독립집합/확률(교집합 있을 수 있음, 각 사건이 서로에게 영향을 미치지 않는 집합)

disjoint =/= independent

disjoint can be dependent but independent cannot be disjoint

P(A and B) = P(A|B)P(B) = P(A|B)P(A)

Bayes’ law P(A|B)P(B)=P(B|A)P(A) <-> P(A|B) = P(B|A)P(A)/P(B) = P(B|A)P(A)/P(B)