Question

Use the following for questions 11-13. Suppose the probability a student from a large university smokes cigarettes is 0.22 and the probability a student is an international student is 0.19. The chance a student from the same university smokes cigarettes and is also an international student is 0.08. 1

Given a randomly student is an international student, what is the probability they are also a smoker?

Given a randomly student is smoker, what is the probability they are an international student?

Are the events being a smoker and international student independent at this university? Why?

Answer 1

1)probability smoker given student is an international student

=P(smoker and international student)/P(international student)=0.08/0.19=0.421053

2)probability they are an international student given student is smoker

=P(smoker and international student)/P(smoker)=0.08/0.22=0.363636

3)

as P(smoker)*P(international student)=0.0418 ; which is not equal to P(smoker and international student) ; therefore  being a smoker and international student is not independent,.