Samples of groundwater were taken from 5 different toxic-waste dump sites by each of 3 different agencies: the EPA, the company that owned each site, and an independent consulting engineer. Each sample was analyzed for the presence of a certain contaminant by whatever laboratory method was customarily used by the agency collecting the sample, with the following results:

Use the \(\alpha=0.05\) level of significance to decide:

(a) Is there reason to believe that the agencies are not consistent with one another in their measurements?

(b) Do the dump sites differ from one another in their level of contamination?

Transcribed Image Text:

Concentration (parts per million) Site A Site B Site C Site D Site E Agency 1 23.8 7.6 15.4 30.6 4.2 Agency 2 19.2 6.8 13.2 22.5 3.9 Agency 3 20.9 5.9 14.0 27.1 3.0