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) Components Life ( Hours) Components

1000-1020 40 1030-1040 339

1020-1040 96 1040-1050 136

1040-1060 364 1050-1060 25

1060-1080 372 1060-1070 20

1080-1100 85 1070-1080 130

1100-1120 43 1080-1090 350 what will be the effectiveness of the measures of dispersion with which we are familiar for comparing the dispersion of the two distributions.