Question

The following are quality control data for a manufacturing process at Kensport Chemical Company. The data show the temperature in degrees centigrade at five points in time during a manufacturing cycle.

Sample	x	R
1	95.72	1.0
2	95.24	0.9
3	95.18	0.7
4	95.46	0.4
5	95.46	0.5
6	95.32	1.1
7	95.40	1.0
8	95.44	0.3
9	95.08	0.2
10	95.50	0.6
11	95.80	0.6
12	95.22	0.2
13	95.60	1.3
14	95.22	0.5
15	95.04	0.8
16	95.72	1.1
17	94.82	0.6
18	95.46	0.5
19	95.60	0.4
20	95.74	0.6

The company is interested in using control charts to monitor the temperature of its manufacturing process. Compute the upper and lower control limits for the R chart. (Round your answers to three decimal places.)

UCL=

LCL=

Answer 1

Sample	x	R
1	95.72	1
2	95.24	0.9
3	95.18	0.7
4	95.46	0.4
5	95.46	0.5
6	95.32	1.1
7	95.4	1
8	95.44	0.3
9	95.08	0.2
10	95.5	0.6
11	95.8	0.6
12	95.22	0.2
13	95.6	1.3
14	95.22	0.5
15	95.04	0.8
16	95.72	1.1
17	94.82	0.6
18	95.46	0.5
19	95.6	0.4
20	95.74	0.6
average	95.401	0.665

x̅̅ =   95.40
R̅ =   0.67
D4=   2.114  
D3=   0  
UCLr = D4*R̅ =        1.406
LCLr = D3*R̅ =       0.000