6816 6676 6688 6828 SolutionWhat is the lower control limit

Solution

What is the lower control limit for the x-bar chart rounded to three decimal places?

              6.816

              6.676

              6.688

              6.828

                                                                                                Range=R

6.91        6.84        6.71        6.76        6.70        6.79        0.21

6.83        6.74        6.75        6.82        6.78        6.71        0.12

6.80        6.72        6.72        6.79        6.72        6.71        0.09

6.74        6.79        6.70        6.71        6.80        6.72        0.10

6.65        6.68        6.79        6.71        6.75        6.72        0.14

Mean of range = 0.132

Lower limit = 6.752-A2* mean of R

A2 for n=6 is 0.483

LCL = 6.752-0.483*0.132

=6.688