13. Baseball Bats A hardwoods manufacturing plant has a production line designed to produce baseball bats weighing 900 grams. During a period of time when the production process was known to be in statistical control, the average bat weight was found to be 892 grams.

The observed data were gathered from 50 samples, each consisting of 5 measurements. The standard deviation of all samples was found to be s55.857 grams. Construct an x -chart to monitor the 900-gram bat production process.