Table 2.
Summary of mean CD4+ cell counts, uncertainties and the observed χ2 values
Weighted mean value  μL−1
|
Uncertainty of mean value  μL−1
|
Standard deviation  μL−1
|
Number of measurement values n | Expansion factor k | χ2 | Consistency test | |
|---|---|---|---|---|---|---|---|
| Dilution 1 | 300.4 | 7.3 | 28.2 | 21 | 2.080 | 199.7 | Negative |
| Dilution 2 | 302.9 | 6.4 | 28.3 | 23 | 2.069 | 163.5 | Negative |
| Dilution 1 | 302.5 | 7.4 | 30.5 | 24 | 2.064 | 121.6 | Negative |
| Dilution 2 | 286.2 | 5.5 | 22.5 | 23 | 2.069 | 91.3 | Negative |
The first two lines represent the values calculated from data reported by participants and the last two lines show values from the centralized analysis. Results for the weighted mean values, combined uncertainties, standard deviation
for a single participants' result, the number of measurement results, the corresponding expansion factor for a 95% level of confidence and chi-squared (χ2) test for consistency are given.