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प्रश्न
Define the mean chart
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उत्तर
The mean chart `(bar"X" "chart")` is used to show, the quality average of the samples taken from the given process.
The `bar"X"` charts are usually required for decision making to accept or reject the process.
Procedure for `bar"X"`
i. Let X1, X2, X3, etc. be the samples selected each containing “n” observations usually (n = 4.5 or 6)
ii. Calculate mean for each samples `bar"X"_1, bar"X"_2, bar"X"_3`, ......... by using `bar"X"_"i" = (sum"X"_"i")/"n"`, i = 1, 2, 3, 4, ….
Where `sum"X"_"i"` = Total f “n” values included in the sample X1.
iii. Find the mean `(bar"X")` of the sample means
`bar"X" = (sumbar"X")/"Number of samples"`
Where `sumbar"X"` = Total of all the sample means.
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संबंधित प्रश्न
What do you mean by product control?
Define R chart
Write the control limits for the mean chart
Write the control limits for the R chart
The following data show the values of sample mean `(bar"X")` and its range (R) for the samples of size five each. Calculate the values for control limits for mean, range chart and determine whether the process is in control.
| 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 |
(conversion factors for n = 5, A2 = 0.58, D3 = 0 and D4 = 2.115)
Choose the correct alternative:
How many causes of variation will affect the quality of a product?
Choose the correct alternative:
Variations due to natural disorder is known as
Choose the correct alternative:
The upper control limit for `bar"X"` chart is given by
From the following data, calculate the control limits for the mean and range chart.
| Sample No. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| Sample Observations |
50 | 21 | 50 | 48 | 46 | 55 | 45 | 50 | 47 | 56 |
| 55 | 50 | 53 | 53 | 50 | 51 | 48 | 56 | 53 | 53 | |
| 52 | 53 | 48 | 50 | 44 | 56 | 53 | 54 | 549 | 55 | |
| 49 | 50 | 52 | 51 | 48 | 47 | 48 | 53 | 52 | 54 | |
| 54 | 46 | 47 | 53 | 47 | 51 | 51 | 47 | 54 | 52 |
The following data gives the average life(in hours) and range of 12 samples of 5lamps each. The data are
| 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 |
Construct control charts for mean and range. Comment on the control limits.
