Question

Excel

Obs	Xbar	Range
1	476	65
2	466	7
3	484	76
4	466	44
5	470	68
6	494	30
7	486	42
8	496	56
9	488	78
10	482	4
11	498	0
12	464	37
13	484	63
14	482	64
15	506	54
16	496	63
17	478	50
18	484	80
19	506	3
20	476	57
21	485	46
22	490	46
23	463	53
24	469	30
25	474	42

Assume a subgroup size = 6

1. Determine trial central line for Xbar & R
2. Determine trial limits for Xbar & R (be careful of formulas, different for R than s charts)
3. Plot charts and align (used in pairs, should have the same size and x-axis scale)
4. Assume points outside trial limits had assignable causes, mark accordingly
5. Copy the completed trial worksheet as the next worksheet in the same workbook file, determine revised central line, limits and plot without the points that had assignable causes (do not delete the rows, only the specific values that were outside the limits.
6. On a third worksheet, Rework trial limits had the subgroup size been 8. Assuming points outside the limits had assignable causes, mark these points. On the fourth worksheet provide the revised limits for the subgroup size of 8.
7. Provide a text box with your observations noting the difference in values for the same data subgroup size of 6 and then 8. Explain the next step for production of this item..

Answer 1