The (score) values for a subject (subject1) tuples are in increasing order:

13, 15, 16, 16, 19, 20, 20, 21, 22, 22, 25, 25, 25, 25, 30, 33, 33, 35, 35, 35, 35, 36, 40, 45, 46, 52, 70

(1) Normalize a value 20 based on min-max normalization

(2) Normalize a value 20 based on z-score normalization.

(3) Explain why often normalize attribute values before analysis.