Question

Polychlorinated biphenyls (PCBs), used in the manufacture of large electrical transformers and capacitors, are extremely hazardous contaminants when released into the environment. The Environmental Protection Agency (EPA) is experimenting with a new device for measuring PCB concentration in fish. To check the precision of the new instrument, seven PCB readings were taken on the same fish sample. The data are recorded in below table (in parts per million). Suppose the EPA requires an instrument that yields PCB readings with a variance of less than 0.1. Does the new instrument meet the EPA’s specifications? Test using α=0.05

PCB Readings							Variance
6.2	5.8	5.7	6.3	5.9	5.8	6	0.0495

Answer 1