Biology and Environmental Science
Benzene, toluene, ethylbenzene, m-, p-xylenes, and o-xylene are volatile organic compounds that are found in residential environments and can cause severe health problems, for example, dizziness, tremors, eye, ear, and throat irritation. The Canadian Health Measures Survey was administered to more than 5000 individuals in order to predict the presence of these compounds. Suppose a random sample of these respondents was selected, and the concentration of toluene was measured in each residence (in mg/m3). The results are given in the following table.
Assume all three underlying populations are normal, with equal variances. Conduct the appropriate hypothesis tests to determine which pairs of population mean toluene levels are different. Use a = 0.01 in each test.