1. In the manufacture of a certain scientific instrument great importance is attached to the life of a critical component. This component is obtained in bulk from two sources, A and B, and in a course of inspection, the lives of 1000 of the components from each source are determined. The following frequency tables are obtained:

Source A source B

life hours No of components life hours no of components

1000-1020 1030-1040

1020-1040 1040-1050

1040-1060 1050-1060

1060-1080 1060-1070

1080-1100 1070-1080

1100-1120 1080-1090

What will be the effectiveness of the measures of dispersion with which we are familiar for comparing the dispersion of the two distributions.