Problem:

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. 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:

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
                                        
Required:

Question 1) Develop an X-chart and an R-chart and plot the values. From the charts, what comments can you make about the process? Solve the given numerical problem and illustrate step by step calculation.