For a production process for which there is a great deal of data since its last modification, the population mean and population standard deviation

For a production process for which there is a great deal of data since its last modification, the population mean μ and population standard deviation σ are assumed known. For such a process, we have the following values (using additional statistical analysis):

The values of A, d_2, D₂, and D₁ are found in the table of control chart factors in Example 2 (Table 22.2).

After bottling, the volume of soft drink in six sample bottles is checked each 10 min. For this process μ = 750.0mL and σ = 2.2mL. Find the central line, UCL, and LCL for the range.

x chart: central line R chart: central line = do, UCL = , UCL = + Ao, LCL = - Ao Do, LCL Do = =