Problem 13-9
Resistors for electronic circuits are manufactured on ahigh-speed automated machine. The machine is set up to produce alarge 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 usedthroughout the run, 15 samples were taken with four resistors ineach sample. The complete list of samples and their measured valuesare as follows: Use three-sigma control limits.
| SAMPLE NUMBER | READINGS (IN OHMS) |
| 1 | | 1010 | 991 | 985 | 986 |
| 2 | | 995 | 996 | 1009 | 994 |
| 3 | | 990 | 1003 | 1015 | 1008 |
| 4 | | 1015 | 1020 | 1009 | 998 |
| 5 | | 1013 | 1019 | 1005 | 993 |
| 6 | | 994 | 1001 | 994 | 1005 |
| 7 | | 989 | 992 | 982 | 1020 |
| 8 | | 1001 | 986 | 996 | 996 |
| 9 | | 1006 | 989 | 1005 | 1007 |
| 10 | | 992 | 1007 | 1006 | 979 |
| 11 | | 996 | 1006 | 997 | 989 |
| 12 | | 1019 | 996 | 991 | 1011 |
| 13 | | 981 | 991 | 989 | 1003 |
| 14 | | 999 | 993 | 988 | 984 |
| 15 | | 1013 | 1002 | 1005 | 992 |
|
a. Calculate the mean and range for the abovesamples. (Round "Mean" to 2 decimal places and "Range" tothe nearest whole number.)
b. Determine X=X= and R?R? . (Roundyour answers to 3 decimal places.)
c. Determine the UCL and LCL for a X?X? chart.(Round your answers to 3 decimal places.)
d. Determine the UCL and LCL forR-chart. (Leave no cells blank - be certain toenter "0" wherever required. Round your answers to 3 decimalplaces.)
e. What comment can you make about theprocess?
o The process is in statistical control.
o The process is out of statistical control.
