Question

Twelve​ samples, each containing five​ parts, were taken from a process that produces steel rods at Emmanual​ Kodzi's factory. The length of each rod in the samples was determined. The results were tabulated and sample means and ranges were computed.

Refer to Table S6.1 - Factors for computing control chart limits (3 sigma) for this problem.

Sample ​Size, n	Mean​ Factor, A2	Upper​ Range, D4	Lower​ Range, D3
2	1.880	3.268	0
3	1.023	2.574	0
4	0.729	2.282	0
5	0.577	2.115	0
6	0.483	2.004	0
7	0.419	1.924	0.076
8	0.373	1.864	0.136
9	0.337	1.816	0.184
10	0.308	1.777	0.223
12	0.266	1.716	0.284

Sample   Sample Mean (in.)   Range (in.)   Sample   Sample Mean (in.)   Range (in.)
1   12.602   0.044   7   12.603   0.021
2   12.600   0.051   8   12.607   0.058
3   12.591   0.042   9   12.597   0.039
4   12.604   0.037   10   12.601   0.038
5   12.599   0.048   11   12.601   0.054
6   12.601   0.053   12   12.606   0.061

- For the given data, the x-double bar = ? inches (round you response to four decimal places).

- Based on the sampling done, the control limits for 3 sigma x-bar chart are:

Upper Control Limit (UCL) = ? inches (round your response to four decimal places).

Lower Control Limit (LCL) = ? inches (round your response to four decimal places).

Based on the x-bar chart, is one or more samples beyond the control limits? yes?/no?

For the given data, the R-bar = ? inches (round your response to four decimal places).

- The control limits for the 3-sigma R-Chart are:

   Upper Control Limit (UCL) = ? inches (round your response to four decimal places).

Lower Control Limit (LCL) = ? inches (round your response to four decimal places).

Based on the R-chart, is one or more samples beyond the control limits? Yes?/No?

Answer 1