A company that tracks the use of its web sine deter- mined that the more pages a visitor views, the more likely the visitor is to provide contact information. Use the following tables to answer the questions: Number of pages viewed: Percentage of visitors: Percentage of visitors in each page-view category that provide 12 3 4 or more 40 30 20 10 contact information: 10 10 20 40

(a) What is the probability that a visitor to the Web site provides contact information?

(b) If a visitor provides contact information, what is the probability that the visitor viewed four or more pages?