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Estimating Methods, Variability, and Sampling for Drop-Test Data

Appendix (Continued)

Error Variance Estimate for GPC

The error variance estimator for triangulated gpc values is:

Where Vˆ (triangulation) is the triangulation variance. Vˆ (cups) is the variance for empty cups, and Vˆ (lids) is the variance for empty lids. n_c and n_l are the number of cups and the number of lids, respectively. 0.124087 is a constant that converts grams of retardant with density 1.095 grams per milliliter into gpc.

Mean square error (MSE) is an estimate of the triangulation variance. The three MSEs are 0.215, 0.262, and 0.256, which is an average MSE of 0.244.

0.003804 = [0.244 + 0.000000532 + 0.0000001597] * 0.124087²

Variance around triangulated gpc = 0.0038. Standard deviation around triangulated gpc = 0.0616.

Appendix continued...

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