A sample of 12 random detectors of a certain type was selected, and each was exposed to 100 pCi/L of radon. The resulting readings were as follows:
104.3 89.6 89.9 95.6 95.2 90.0
98.8 103.7 98.3 106.4 102.0 91.1
Does this data suggest that the population mean reading under these conditions differs from 100? State and test the appropriate hypotheses using =.05.