Define the mean chart

Question

Sum

Solution

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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Statistical Quality Control (SQC)

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Q 9 Q 8 Q 10

Chapter 9: Applied Statistics - Exercise 9.3 [Page 226]

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Samacheer Kalvi Business Mathematics and Statistics [English] Class 12 TN Board

Chapter 9 Applied Statistics
Exercise 9.3 | Q 9 | Page 226

RELATED QUESTIONS

Define chance cause

Name the control charts for variables

Construct `bar"X"` and R charts for the following data:

Sample Number	Observations
1	32	36	42
2	28	32	40
3	39	52	28
4	50	42	31
5	42	45	34
6	50	29	21
7	44	52	35
8	22	35	44

(Given for n = 3, A₂ = 1.023, D₃ = 0 and D₄ = 2.574)

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)