Refer to Table S6.1 - Factors for Computing Control Chart Limits (3 sigma)

Sample

Size, n

Mean Factor,

A2

Upper Range,

D4

Lower Range,

D3

2

1.880

3.268

0

3

1.023

2.574

0

4

0.729

2.282

0

5

0.577

2.115

0

6

0.483

2.004

0

7

0.419

1.924

0.076

8

0.373

1.864

0.136

9

0.337

1.816

0.184

10

0.308

1.777

0.223

12

0.266

1.716

0.284

LOADING...

for this problem.

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	x	R	Hour	x	R	Hour	x	R	Hour	x	R
1	3.15"	0.71"	7	2.95"	0.48"	13	3.21"	0.80"	19	4.51"	1.66"
2	3.10	1.23	8	2.65	1.13	14	2.93	1.36	20	2.79	1.14
3	3.12	1.43	9	3.02	0.66	15	3.02	1.06	21	2.75	1.08
4	3.39	1.26	10	2.75	1.28	16	2.74	0.50	22	3.38	0.41
5	3.07	1.12	11	2.83	1.12	17	2.76	1.38	23	2.94	1.53
6	2.76	0.37	12	2.87	0.45	18	2.84	1.29	24	2.64	0.92

Based on the sampling done,

the

control limits for 3-sigma

x

chart are (round all intermediate calculations to three decimal places before proceeding with further

calculations):

Upper Control Limit

(UCLx)

(LCLx)

Based on the x-bar chart, the wire cutting process has been IN CONTROL OR OUT OF CONTROL?

Calculate the UCLr and LCLr for R-chart