A quality control analyst for a light bulb manufacturer is c
A quality control analyst for a light bulb manufacturer is concerned that the time it takes to produce a batch of light bulbs is too erratic. Accordingly, the analyst randomly surveys 10 production periods each day for 14 days and records the sample mean and range for each day.
Day
X (in minutes)
R
1
58.5
5.1
2
47.6
7.8
3
64.3
6.1
4
60.6
5.7
5
63.7
6.2
6
57.5
6
7
55
5.4
8
62.7
6.1
9
61.9
5.9
10
60
5
11
58.3
7.1
12
52
6.5
13
58.3
5.9
14
52
5.2
Referring to the table above, suppose the analyst constructs an X chart to see if the production process is in control. What is the upper control limit (UCL) for this chart? Round your answer to the nearest hundredth.
62.15
60.95
59.41
56.89
| Day | X (in minutes) | R |
| 1 | 58.5 | 5.1 |
| 2 | 47.6 | 7.8 |
| 3 | 64.3 | 6.1 |
| 4 | 60.6 | 5.7 |
| 5 | 63.7 | 6.2 |
| 6 | 57.5 | 6 |
| 7 | 55 | 5.4 |
| 8 | 62.7 | 6.1 |
| 9 | 61.9 | 5.9 |
| 10 | 60 | 5 |
| 11 | 58.3 | 7.1 |
| 12 | 52 | 6.5 |
| 13 | 58.3 | 5.9 |
| 14 | 52 | 5.2 |
Solution
60.95
B
Diff: 2
Keywords: R chart, center line


