b. [25] Your goal is to write functions that act on a dictionary containing the names of students as keys, and their exam score as the values. An example dictionary is as follows: {'Kathy': 68, 'Mira': 94, 'Brian': 44, 'Fred': 90} i) A function Make Average () that takes such a dictionary as a parameter and returns the average score in the class. (You are NOT allowed to use any built-in functions that compute the average or sum of values) ii) A function FindStars () that takes such a dictionary as a parameter and returns a list containing students that scored 90 or higher iii) A function GradeBook () that takes such a dictionary as a parameter and returns another dictionary whose keys are the names of the students and the values are "EXCELLENT", "PASS", or "FAIL" determined as follows: FAIL if the exam score = 50 but = 90