15. Respiratory rate (breaths per minute) was measured in eight experimental animals under three levels of exposure to carbon monoxide. The results were as follows.

Animal Exposure Level Low Moderate High 1 36 43 45 2 33 38 39 3 35 41 33 4 39 34 39 5 41 28 33 6 41 44 26 7 44 30 39 8 45 31 29 Can one conclude on the basis of these data that the three exposure levels, on the average, have a different effect on respiratory rate? Let a = .05. Determine the p value.