In: Statistics and Probability
According to the Consumer Electronics Manufacturers Association, 10% of all U.S households have a fax machine and 52% have a personal computer. Suppose 91% of all U.S households having a fax machine also have a personal computer. a. What is the probability that a randomly selected US household has a fax machine and a personal computer? b. What is the probability that a randomly selected US household has a fax machine or personal computer? c. What is the probability that a randomly selected US household has a fax machine and does not have a personal computer? d. Are the events fax machine and personal computer independent? Why?
Let A = Event that household have fax machine
B = Event that household have personal computer
We have,
P(A) = 0.10 P(B) = 0.52 P(B/A) = 0.91
(a) Consider,
By conditional probability
Hence, P( A and B) = 0.091
(b) Consider,
P(A or B) =
By Addition theorem
Hence, P(A or B) = 0.529
(c) Consider,
Hence, P(A and not B) = 0.009