I need help with this Lean Six Sigma question:

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Data:

Case Study File Name: Phone Plates.jmp 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? Justify your answer. Phone Plates - JMP Pro File Edit Tables Rows Cols DOE Analyze Graph Tools View Window Help - Phone Plates Sample Length 1 Length 2 Length 3 Length 4 Length 5 - Columns (6/0) Whample Length 1