In: Statistics and Probability
The urinary fluoride concentration was measured both for a sample of livestock grazing in an area previously exposed to fluoride pollution, and for a sample grazing in an unpolluted region:
polluted | unpolluted |
21.3 | 14.2 |
18.7 | 18.3 |
23.0 | 17.2 |
17.1 | 18.4 |
16.8 | 20 |
20.9 | |
19.7 |
Do the data strongly indicate that the distribution for fluoride concentration for livestock grazing in the polluted region is hoisted to the right of that for livestock grazing in the unpolluted region? Use alpha = .10. (Population is not normally distributed, use Mann-Whitney U-test).