A company that manufactures injected molded plastics for phone casings considers the length of the plate a critical dimension in assessing quality. The team has completed a six sigma project to improve variation in the plate length. They are now monitoring the new process using an SPC chart. They randomly select 5 consecutively manufactured plates from the line and check for process changes.
a) What type of control chart should be used, and why?
b) Is the process in statistical control?
