X=3

X company manufactures quality garments by the implementation of SPC in their production line. They are very concern about stitch quality. The number of stitch faults observed in their 20 shirts are given in the table. x is any number after the 7th digit of your student number, that is larger than 2 . (Use x=3 if all numbers are smaller than 3 ) a) Which chart will you use to discuss if the process is statistically under control? Please explain why do you chose this chart. ( 2 pts) b) Draw the diagrams by using the formula given in the appendix and discuss if the process in under control statiscally. (18 pts)