Facebook reports that 70% of their users are from outside the United States and that 50% of their users log on to Facebook every day. Suppose that 20% of their users are United States users who log on every day.
a) What percentage of Facebook's users are from the United States?
b) What type of probability is the 20% mentioned above?
c) Construct a contingency table showing all the joint and marginal probabilities.
d) What is the probability that a user is from the United States given that he or she logs on every day?
e) Are From United States and Log on Every Day indepen- dent? Explain.