Question: STAYING IN TOUCH In a poll conducted in 2007, 2000 adults ages 18 yr and older were asked how frequently they are in touch with their parents by phone. The results of the poll are as follows:
If a person who participated in the poll is selected at random, what is the probability that the person said he or she kept in touch with his or her parents
a. Once a week?
b. At least once a week?