9. (8 points) A class group project requires students to work in groups of 6. Within a certain group, suppose that the probability that any given group member does their fair share of the work is 0.63. Round all answers to four decimal places. Hint: Use a binomial distribution. a) Find the probability that exactly 4 group members do their fair share. b) Find the probability that at least 5 group members do their fair share