Olá, para quem estiver participando do curso Harvard Public Health: Quantitative analysis in Clinical and Public Health e, gostaria de ter espaço para discutir a respeito das aulas, estudos, artigos interessantes e homework, criei este fórum reservado.
Antes de colocar um tópico novo, verifique os comentários para responder ao aberto.
Obrigada!
Sejam bem vindos!
Bianca
Grupo de discussão
Comente em nosso fórum, adicione artigos, links de interesse, tópicos, etc!!!
Fórum - Harvard Public Health
———
Hi,
This is an internationacional forum created for participants in the Harvard Public Health Course. Post comments, studies, articles, describe how you got your homework results, etc.
Before open a new topic, read the forum and participe in the open discution.
Thanks,
Welcome!!!
Bianca
———
As we saw last week, the probability theory is based on the assumption that we have a random variable. First, we saw probability based on events occurence, which is represented by occurence or not occurence of some event measured.
In the Venn Diagram, we learned how to express our events, so:
When we have the INTERSECTION of two events:
A∩B, is defined by BOTH A and B, so:
P(A∩B) = P(A) + P(B)
When we have the UNION of A and B:
A∪B, either A OR B, or both A and B, so:
P (A∪B) = P(A)+P(B)-P(A)*P(B)
The complement is the NOT occurence of the event, and is done by:
P(Ac)=1-P(A)
Here, when we do the P(A∪Ac)= either A or Ac to occur, or both. This is = 1.
When we use P(A∩Ac)=∅, or null event, because those events cannot occur simultaneously, they are MUTUALLY EXCLUSIVE.
When two events are not mutually exclusive than:
P(A∪B)=P(A)+P(B)-P(A∩B)
The conditional probability is used when we have 2 events, and we want to know if one changes given the occurence of the other.
The multiplicative rule of probability states: P(A∩B)=P(A)*P(B|A) or,
P(B|A)=P(A∩B)/P(A).
