The accompanying data represent the pulse rates (beats per minute) of nine students. Treat the nine students as a population. Compute the z-scores for all the students. Compute the mean and standard deviation of these z-scores. Student Pulse Student 1 (76), Student 2 (61), Student 3 (60), Student 4 (81), Student 5 (72), Student 6 (80), Student 7 (80), Student 8 (68), Student 9 (73)