Samples of 12-volt batteries are taken at 30-minute intervals during a production run. Each sample consists of 3 batteries, and a technician records how long each battery will produce 400 amperes during a standard test. Given the following data, also listed in file XR20042, construct 3-sigma mean and range control charts and evaluate whether the process is in control.

Transcribed Image Text:

Minutes, Battery Number Sample Number 13.3 12.2 11.2 7.8 10.1 9.9 9.4 13.4 8.2 9.7 11.4 11.7 12.1 8.5 9.2 10.0 13.8 8.5 4