A manufacturer of dustless chalk instituted a quality control program to monitor chalk d...

A manufacturer of dustless chalk instituted a quality control program to monitor chalk density. The sample standard deviations of densities for 24 different subgroups, each consisting n = 8 of chalk specimens, were as follows:

Calculate limits for an S chart, construct the chart, and check for out-of-control points. If there is an out-of-control point, delete it and repeat the process