Your firm is interested in learning more about customers’ purchasing patterns on its Web site and how they relate to the frequency of online site visits. The probability that a customer’s visit will result in a purchase is 0.35. The probability that a customer has been to the site within the past month is 0.20. Of those who did not buy anything, 12% had been there within the past month. 

a. Draw a probability tree for this situation. 

b. Find the conditional probability of making a purchase given that the customer had been to the site within the past month. 

c. What percent of customers are frequent shoppers, defined as making a purchase and having been to the site within the past month?