Calculate control limits for an S chart from the refractive index data of Exercise 11. D...

Calculate control limits for an S chart from the refractive index data of Exercise 11. Does the process appear to be in control with respect to variability? Why or why not?

Reference exercise 11

The accompanying table gives sample means and standard deviations, each based on n = 6 observations of the refractive index of fiber-optic cable. Construct a control chart, and comment on its appearance. and