Hàm nào sau đây không phải là hàm xử lý chuỗi Alphabet *

Asample of 200 rom computer chips was selected on each of 30 consecutive days, and the number of nonconforming chips on each day was as follows: 8, 19, 27, 17, 38, 18, 4, 27, 9, 22, 30, 17, 14, 23, 15, 14, 12, 20, 13, 18, 14, 20, 9, 27, 30, 13, 10, 19, 12, 26. construct a p chart and examine it for any out-of-control points. (round your answers to four decimal places.)