It is estimated that, during the past year, 27% of all adults visited a therapist and 43% of all adults used non-prescription antidepressants. It is also estimated that 21% of all adults both visited a therapist and used a non-prescription antidepressant during the past year. Answer the questions below. (If necessary, consult a list of formulas.) (a) What is the probability that an adult visited a therapist during the past year, given that he or she used non-prescription antidepressants? Round your answer to 2 decimal places. (b) An adult who visited a therapist during the past year is randomly selected. What is the probability this adult used non-prescription antidepressants? Round your answer to 2 decimal places.