Chap 2 Probability Student.pdf

# 2 whats the probability that a randomly selected

• Notes
• 8

This preview shows pages 5–8. Sign up to view the full content.

2. What’s the probability that a randomly selected student from the class is sophomore given they’re a male? 3. What’s the probability that a randomly selected student from the class is male given they’re a sophomore? Example : The probability that Sam parks in a no-parking zone and gets a parking ticket is 0.06, and the probability that Sam cannot find a legal parking spot and has to park in the no-parking zone is 0.20. On Tuesday, Sam arrives at school and has to park in a no-parking zone. Find the probability that he will get a parking ticket. Law of Total Probability : Let be mutually exclusive and exhaustive events and be any event.

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

Bayes Theorem : Let be mutually exclusive and exhaustive events with prior probabilities and be any event for which Then, the posterior probability of given has occurred is given by: Example : A blood test is 99% effective at detecting a certain disease if, in fact, the disease is present. The test also yields a positive result for 1% of the healthy individuals tested. Suppose the disease is quite rare; only 0.5% of the population actually has the disease. If an individual has a positive test what is the probability they actually have the disease?
Note : The Multiplication Rule can be found by taking the conditional probability formula and multiplying both sides by the marginal probability in the denominator. That is, Example :

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

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