on a recent holiday eveing a sample of 1000 driver was stoped by ploice . one hundred and
twenty five were under 30 years of age. a total of 400 were under teh influnce of alcohol.of the
dreivers under 30 years age. 100 were under the influnece of alcohol.
let A be the event that a driver the influince of alcohol.
let y be the event thet a deriver is less than 30 years old .
a. determine P(A) and p(A)
b. what is the probabilty that a driver is under 30 and not under the influence of alcohol?
c. given the driver is not under 30 , what is the probability that he/ she is under the influnce of
alcohol.?
d. what is the probabilty that a drivr is under the influnce of alcohol, when we know the driver is
under 30?
e. show the joint probability table.
f. Are A and Y mutually exclusive?explain
g. Are A and Y indepent events ? explain.
Solution
http://www.ssc.wisc.edu/~gwallace/PA_818/Resources/midterm01_f08a.pdf
go to question 4 in this link .Study this if you still dont get it post a comment here.