The urinary fluoride concentration (parts per million) wasmeasured both for a sample of livestock grazing in an areapreviously exposed to fluoride pollution and for a similar samplegrazing in an unpolluted region:
Polluted. 21.3. 18.7 23.0. 17.1. 16.8. 20.9. 19.7
Unpolluted. 14.2. 18.3. 17.2. 18.4. 20.0
Does the data indicate strongly that true average fluorideconcentration for livestock grazing in the polluted region islarger than for the unpolluted region? Use the appropriate test atlevel α = 0.01.
