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Question
Write the control limits for the mean chart
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Solution
The calculation of control limits for `bar"X"` chart in two different cases are
| Case (i) When `bar"X"` and SD are given |
Case (ii) When `bar"X"` and SD are not given |
|
UCL `\overset{==}{"X"} + sigma/sqrt("n")` CL = `\overset{==}{"X"}` LCL = `\overset{==}{"X"} - 3 sigma/sqrt("n")` |
UCL = `\overset{==}{"X"} + "A"_2 bar"R"` CL = `\overset{==}{"X"}` LCL = `\overset{==}{"X"} - "A"_2bar"R"` |
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| Sample Number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Mean | 11.2 | 11.8 | 10.8 | 11.6 | 11.0 | 9.6 | 10.4 | 9.6 | 10.6 | 10.0 |
| Range | 7 | 4 | 8 | 5 | 7 | 4 | 8 | 4 | 7 | 9 |
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| Sample Number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| `bar"X"` | 29 | 26 | 37 | 34 | 14 | 45 | 39 | 20 | 34 | 23 |
| R | 39 | 10 | 39 | 17 | 12 | 20 | 05 | 21 | 23 | 15 |
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| Sample No | 1 | 2 | 3 | 4 | 5 | 6 |
| Sample Mean | 1080 | 1390 | 1460 | 1380 | 1230 | 1370 |
| Sample Range | 410 | 670 | 180 | 320 | 690 | 450 |
| Sample No | 7 | 8 | 9 | 10 | 11 | 12 |
| Sample Mean | 1310 | 1630 | 1580 | 1510 | 1270 | 1200 |
| Sample Range | 380 | 350 | 270 | 660 | 440 | 310 |
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