Data were collected from a survey given to graduating college seniors on the number of times they had changed majors. From that data, a probability distribution was constructed. The random variable X is defined as the number of times a graduating senior changed majors. It is shown below: ac 0 2 3 4 5 6 7 8 P(X = x) 0.252 0.286 0.13 0. 188 0.082 0.038 0.02 0.003 0.001 a. What is the probability that a randomly selected student changed his or her major at least once? b. What is the probability that a randomly selected student changed his or her major at most twice? c. Given that a randomly selected person did change majors, what is the probability that he or she changed majors more than three times? (Round your answer to three decimal places.)