Statistical Quality Control By Mahajan.pdf Patched -

I notice you're asking for a piece from Statistical Quality Control by (a common textbook for engineering and management students in India).

Interpretation: As long as future sample means lie within (39.74, 40.66) and ranges within (0, 1.69), the process is in statistical control. Statistical Quality Control By Mahajan.pdf

Mahajan emphasizes that the purpose of these charts is not to catch the worker, but to catch the process failure. They provide a visual history of the process capability. I notice you're asking for a piece from

[ UCL_R = D_4 \barR, \quad CL_R = \barR, \quad LCL_R = D_3 \barR ] (A₂, D₃, D₄ are factors depending on n, given in standard tables.) They provide a visual history of the process capability

Acceptance Sampling is reactive. It involves inspecting a random sample from a batch (lot) to decide whether to accept or reject the entire batch.