The following is the measurement data of the turning valve holder, which is produced by a lathe. The specifications specified are between 1.1550 inches and 1.1560 inches. The data below shows the sizes in 1 / 10.000 inch over 1.1550 inch

Kelompok	X1	X2	X3	X4	X5	X	R
1	2	3	3	4	3	3,0	2
2	3	4	4	5	4	4,0	2
3	4	3	5	5	5	4,4	2
4	5	4	6	4	4	4,6	2
5	5	5	6	4	5	5,0	2
6	7	5	6	5	5	5,6	2
7	7	7	7	7	6	6,8	1
8	7	7	8	6	7	7,0	2
9	8	8	8	7	7	7,6	1
10	7	8	7	8	9	7,8	2
11	8	7	9	8	8	8,0	2
12	8	9	9	8	9	8,6	1
13	9	10	9	8	9	9,0	2
14	9	9	10	10	10	9,6	1
15	9	11	9	11	10	10,0	2
16	10	11	11	9	11	10,4	2
17	11	11	12	11	11	10,2	1

a. Draw a suitable control chart until the control chart is considered stable b. Determine the Cp of the process index before and after repair. c. Compare the results and explain their meaning