This experiment concerns the precision of four types of collecting tubes used for air sampling of hydrofluoric acid. Each type is tested three times at five different concentrations. The data shown in Table 4.7 give the differences between the three observed and true concentrations for each level of true concentration for each of the tubes.

The differences are required to have a standard deviation of no more than 0.1.

Do any of the tubes meet this criterion? (Careful: What is the most appropriate sum of squares for this test?)

 LO.1