This assignment solution addresses quality control and process analysis in a manufacturing context. It begins with calculations related to sample size determination, considering factors like allowance, observation time, and acceptable error. The core of the solution focuses on quality control charts, specifically X-bar, R, and C charts. The solution provides step-by-step calculations for determining control limits (UCL and LCL) for both X-bar and R charts, utilizing data on coil spring lengths. It includes the construction and interpretation of these charts, determining whether the process is under control. Furthermore, the solution incorporates run tests and median tests to analyze data patterns. The second part of the assignment delves into the application of c-charts for analyzing defects, calculating control limits and determining whether the process is under control. Finally, the solution calculates production costs and the impact of rework on the overall cost per unit, providing a comprehensive analysis of the manufacturing process and quality control measures.