Following their manufacture, plastic shims are sampled at periodic intervals and their thickness (in millimeters) measured. Each sample consists of n 5 3 shims, and the following data have been collected for the past 20 samples. Given these measurements, use one or more appropriate 3-sigma control charts in evaluating whether the process is in control.

Transcribed Image Text:

Measurement (mm) Sample Number 1 2 3 1234567 47.7 51.8 42.7 55.4 47.9 53.9 51.6 47.9 47.6 4 45.3 45.5 57.4 48.9 49.4 47.0 46.5 46.3 47.5 55.0 44.3 51.1 8 49.5 50.3 43.9 9 53.7 47.6 49.2 10 48.4 49.2 41.8 11 46.7 51.1 43.9 12 48.8 49.8 48.7 13 48.1 48.8 50.9 14 55.6 52.5 42.8 15 54.3 54.6 44.4 16 48.4 48.3 47.6 17 46.2 46.3 50.3 18 52.4 51.8 49.1 19 48.1 51.7 53.5 20 52.7 46.5 49.2