A machine has four heads. Samples of n= 3 units are selected from each head, and the x and R values for an important quality characteristic are computed. The data are shown in Table10E.4. Set up group control charts for this process.

TABLE 10E. Data for Exercise 10.5 4 Head Sample I 2 Number-RRRR 1 53 2 54 56 2 55 3 2 51 1 55 2 54 4 54 4 3 54 2 525 53 3 57 2 4 55 3 54 3 52 1 51 5 5 54 1 50 2 512 53 I 6 53 2 51 154 2 52 2 7 51 1 53 2 58 5 54 1 8 52 2 544 51 2 55 2 9 50 2 52 3 52 53 10 51 1 55 1 53 3 53 5 11 52 3 57 2 52 4 551 12 51 55 54 2 58 2 13 54 4 58 2 51 1 53 I 14 53 1 54 4 503 54 2 15 55 2 52 3 54 2 52 6 16 54 451 1 53 2 58 5 17 53 3 50 2 57 1 53 1 18 52 1 49 1 52 1 49 2 19 5 2 53 3 5 2 50 3 20 52 4 52 2 50 3 52 2