The Goodman Tire and Rubber Company periodically tests its tires for tread wear under simulated road conditions. To study and control the manufacturing process, 20 samples, each containing three radial tires, were chosen from different shifts over several days of operation, with the following results. Assuming that these data were collected when the manufacturing process was believed to be operating in control, develop the R and x¯ charts.
Please see the attached file for the table.
The solution develops R and x¯ charts for Goodman Tire and Rubber Company. The study examines the control of the manufacturing process.