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• It is also to be noted that the data from the two reference areas is weighted in accordance with <br />the original relative abundance of the types in the pre-mining landscape (83% mountain brush, <br />17% sagebrush/snowberry). It was necessary to sample each to adequacy (see below) but in the <br />process of weighting, a reliable estimate of variance is lost. Thus the reference area standard is <br />thereafter in the process treated as a technical standard (i.e. without confidence limits) and one- <br />sample t-testing is used. <br />HYPOTHESIS TESTING APPROACHES <br />For formal hypothesis testing relative to Phase II Bond Release the following procedures were <br />followed: <br />For cases where the mean allowable herbaceous cover of the BRB was greater than the <br />reference area standard, then the hypothesis of reclamation success was tested using a <br />parametric test of the "reverse null" hypothesis. This was conducted using the following <br />expression (CDMG 2005 revised rule, 4.15.11 (2)(c)): <br />• x-Q <br />S- <br />Where: x = Bond Release Block Sample Mean <br />Q = 90% of Standard <br />S_ = Standard error of mean [s l Vn <br />X <br />S = Sample standard deviation <br />n = Sample size <br />t, = Calculated t value <br />tt = Table t value'(alpha = 0.2) see Rohlf and Sokal 1969 <br />If tc was greater than the 1-tailed t table value for alpha error probability of .20, with (n-1) degrees <br />of freedom then Ho would be rejected, and revegetation was deemed successful. <br />For cases where the mean allowable herbaceous cover of an adequate sample from the 2010 <br />Phase II BRB was less than 90% of the cover standard (see above), then a one-sample t-test <br />0 6