CP-Clarification

# CP-Clarification - Conditional Probability Clarification of...

This preview shows pages 1–3. Sign up to view the full content.

Conditional Probability Clarification of Tree View Ramesh Yerraballi

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Tree View In the tree view for conditional probability each node represents an event of interest to us. The branches of the tree are labeled by the probabilities that the branch in question is taken, i.e., the occurrence probability leading from one to the next node. Here is the example we looked in class: P(F) P(F c ) P(S | F) P(S c | F) P(S c | F c ) P(S | F c ) F F c S F S c F S c F c S F c F: Event that the first doctor made a positive diagnosis P(F) = 0.1 (10%) S: Event that the second doctor made a positive diagnosis P(S) = 0.17 (17%) F S : Event that both doctors made a positive diagnosis P(F S) = 0.08 (8%) We are asked to find, “the probability that the second doctor makes a positive diagnosis given that the first has made a negative diagnosis”: P(S | F c ) By definition of Conditional probability: P(S | F c ) = P(S F c ) / P(F c ) = (P(S) - P(F S)) / (1-P(F c ) = (0.17 - 0.08) / (1 - 0.9) = 0.1
Tree View We note that we can solve for other possible answers too by applying probability properties we already know: P(F)=0.1 P(F c )=0.9 P(S | F) = 0.8 P(S c | F) = 0.2 P(S c | F c ) = 0.9 P(S | F c ) = 0.1 F F c P(S F) = 0.08
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern