Sampling 4 pieces of precision-cut wire (to be used in computer assembly) every hour for the past 24 hours has produced the following results:
|Hour |Average (inches)|R (inches) |Hour |Average[pic] |R (inches) |
| | | | |(inches) | |
|1 |3.25 |0.71 |13 |3.11 |0.85 |
|2 |3.10 |1.18 |14 |2.83 |1.31 |
|3 |3.22 |1.43 |15 |3.12 |1.06 |
|4 |3.39 |1.26 |16 |2.84 |0.50 |
|5 |3.07 |1.17 |17 |2.86 |1.43 |
|6 |2.86 |0.32 |18 |2.74 |1.29 |
|7 |3.05 |0.53 |19 |3.41 |1.61 |
|8 |2.65 |1.13 |20 |2.89 |1.09 |
|9 |3.02 |0.71 |21 |2.65 |1.08 |
|10 |2.85 |1.33 |22 |3.28 |0.46 |
|11 |2.83 |1.17 |23 |2.94 |1.58 |
|12 |2.97 |0.40 |24 |2.64 |0.97 |
Develop appropriate control charts and determine whether there is any cause for concern in the cutting process. Plot the information and look for patterns.
Ten eerste moeten we eerst de boven-en ondergrens berekenen voor zowel voor een [pic] chart grafiek en R chart.
Voor de grafiek met de gemiddelde inches is [pic] and [pic]:
[pic] [pic] [pic]
Of (2.236,