Question

Resistors for electronic circuits are manufactured on a high-speed automated machine. The machine is set up to produce a large run of resistors of 1,000 ohms each. Use Exhibit 10.13.

     To set up the machine and to create a control chart to be used throughout the run, 15 samples were taken with four resistors in each sample. The complete list of samples and their measured values are as follows: Use three-sigma control limits.

SAMPLE NUMBER		READINGS (IN OHMS)
1		1099	1087	975	989
2		1023	991	1024	981
3		988	973	997	993
4		1016	1016	987	1025
5		1012	1013	977	999
6		999	1022	1027	983
7		1028	996	1017	1001
8		1029	989	1023	996
9		1004	1003	1023	997
10		1018	1008	1001	1007
11		1003	1007	986	992
12		992	988	1000	1005
13		1024	980	986	985
14		1024	975	1017	984
15		1003	1008	981	1009

a. Calculate the mean and range for the above samples. (Round "Mean" to 2 decimal places and "Range" to the nearest whole number.)

Sample Number	Mean	Range
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15

b. Determine X=X= and R−R−. (Round your answers to 3 decimal places.)

X=X=
R−R−

c. Determine the UCL and LCL for a X−X−chart. (Round your answers to 3 decimal places.)

UCL
LCL

d. Determine the UCL and LCL for R-chart. (Leave no cells blank - be certain to enter "0" wherever required. Round your answers to 3 decimal places.)

UCL
LCL

e. What comments can you make about the process?

	The process is out of statistical control.
	The process is in statistical control.

Answer 1