TABLE 4.2
STATISTICAL SUMMARY - 1,4 DIOXANE
NO-PURGE SAMPLER DEMONSTRATION
McCLELLAN AFB, CALIFORNIA

a/ Values between 1 and 10 are highlighted in pink. Statistical results of these comparisons are of very low confidence.

b/ Values between 90 and 100 are highlighted in yellow and indicate that the two populations were statistically different.
Value in parentheses indicates the percentage of times Sampler A concentration was greater than Sampler B concentration.

c/ Values between 90 and 100 percent and highlighted in yellow indicate that the two populations being compared are statistically different.

d/ RPD = Relative Percent Difference.
A positive value indicates that the concentration in Sampler A was typically greater than the concentration in Sampler B.
A negative value indicates that the concentration in Sampler B was typically greater than the concentration in Sampler A.
Values between -10 and 10 indicate that the two populations are similar.
Values not between -10 and 10 and highlighted in yellow indicate that the two populations are different.

e/ Slopes between 0.90 and 1.10 indicate the populations are similar.
Slopes less than 0.90 and highlighted in yellow indicate that the concentration in Sampler A was typically greater than the concentration in Sampler B.
Slopes greater than 1.10 and highlighted in yellow indicate that the concentration in Sampler B was typically greater than the concentration in Sampler A.
R2 values less than 0.90 indicate a greater degree of scatter and a lower confidence that the slope value is meaningful.
R2 values greater than 0.90 indicate a lower degree of scatter and a higher confidence that the slope value is meaningful.

f/ An assessment of all statistical and quantitative comparative tests was performed and a holistic qualitative statement regarding the results was made.
Conclusions highlighted in green are deemed to be valid since all tests resulted in the same observation.
Conclusions highlighted in orange are assigned a lower degree of confidence since the results of all tests did not result in the same observation.
Conclusions highlighted in pink are assigned the lowest degree of confidence since too few data points were available for statistical significance.