Consider drained weights of the contents of cans of Brand X green beans. Believable values for the process mean and standard deviation of these weights are 21.0 oz and 1.0 oz, respectively. Suppose that in a Brand X canning factory, 8 of these cans are sampled every hour and their net contents determined. Sample means and ranges are then computed and used to monitor stability of the filling process.
(a) What is the name and value of the multiplier of σ = 1.0 that would be used to establish a center line for sample ranges?
(b) What are the names and values of the multipliers of σ = 1.0 that would be used to establish upper and lower control limits for sample ranges?
(c) What center line and control limits should be established for sample means?