(b) In the manufacturing of a certain scientific instrument great importance is attached to the life of a particular critical component. This component is obtained in bulk from two sources, A and B,...

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