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t = The (a=.10) t -table value for a 1 tail t-test, n-1 degrees of <br />freedom (infinite degrees of freedom may be used if n>30) <br />see Rohlf and Sokal 1969 <br />n =Sample size <br />All such calculations were based on data from a minimum of fifteen samples <br />NOTES ON THE COMPARISON OF DATA TO APPLICABLE REFERENCE AREA STANDARDS <br />Upon the formal comparison of cover data from reclaimed areas to applicable performance <br />standards, observed total all -hit herbaceous cover percentage must be adjusted for excessive <br />contribution by annual / biennial species (CDMG 1995, Guidelines Regarding Selected Coal Mine <br />Bond Release Issues, 1 (IV)A(4)). Herbaceous cover values used in such comparisons also must <br />exclude values for species present on the Routt County Prohibited or Restricted Noxious list or <br />that are listed as noxious by the State of Colorado (Colorado Dept. of Agriculture, Division of <br />Plant Industry, Title 35, Article 5.5, 101-119, Lists A and B of Rules as replaced 2003). <br />For purposes of assessment of reclamation adequacy, all -hit herbaceous cover data from <br />reference area sampling is used as per Sage Creek Mine permit provisions. <br />HYPOTHESIS TESTING APPROACHES <br />For formal hypothesis testing relative to Phase II Bond Release the following procedures were <br />followed: <br />Were where the mean allowable herbaceous cover of the BRB to be greater than the reference <br />area standard, then the hypothesis of reclamation success would be tested using a parametric <br />test of the "reverse null' hypothesis. This would be conducted using the following expression <br />(CDMG 2005 revised rule, 4.15.11 (2)(c)): <br />tc _ <br />X <br />S - <br />x <br />Where: x = Bond Release Block Sample Mean <br />0 = 90% of Standard <br />S- = Standard error of mean [ s / V ] <br />x <br />S = Sample standard deviation <br />5 <br />