Changing major distribution. 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 a is defined as the number of times a graduating senior changed majors. It is shown below along with the corresponding probabilities: 2 P(x) 0 0.220 1 2 0.500 3 0 0.110 4 0.170 Report all probabilities to three significant figures. (a) What is the probability that a randomly selected student changed his or her major only once? (b) What is the probability that a randomly selected student changed his or her major exactly three times? (c) What is the probability that a randomly selected student changed his or her major 1 or 0 times?