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• If: The mean herbaceous cover or production of an adeq uate sample from BRB -3 is less than 90% of the cover <br />standard (see above), then a one - sample t -test will be made in the following form to test the hypothesis of reclamation <br />success far cover (CDMG Coal Rules, 4.13.11 (2)(b)): <br />S- <br />X <br />Where: <br />x = Bond Release Block Sample Mean <br />Q = 90% of Standard �— <br />S- = Standard error of mean [ s l �V n ] <br />X <br />S = Sample standard deviation <br />n = Sample size <br />t = Calculated t value <br />t = Table t value <br />The null hypothesis being tested is that the bond release block mean (µ) is greater than or equal to <br />90% of the standard, stated as H µ >_ Q. If t is less than or equal to the 1- tailed t table value for <br />alpha error probability of .10, at (n -1) degrees of freedom (infinite degrees of freedom may be used if <br />n >30), then Ho is not rejected, and revegetation is deemed successful for the parameter tested. <br />If Sample adequacy for herbaceous cover or production has not been achieved in BRB -3 and a total of 30 or more <br />samples have been taken, and the means for total herbaceous foliar cover or herbaceous production in the BRB <br />reclaimed area exceed 90% of the reference area - derived standard, then the hypothesis of reclamation success mill he <br />tested under the conditions a `reverse null" approach using a parametric test of the `reverse null' hypothesis. This <br />mould be conducted using the following expression (CDMG Coal Rules, 4.13.11 (2)(c)): <br />• t = x —Q <br />SX <br />Where: <br />x = Bond Release Block Sample Mean <br />Q = 90% of Standard <br />S- = Standard error of mean [ s / V in ] <br />x <br />S = Sample standard deviation <br />n = Sample size <br />t = Calculated t value <br />t = Table t value <br />The null hypothesis being tested is that the bond release block mean (p) is less than or equal to 90% <br />of the standard, stated as H g <_ Q. If t is greater than the 1- tailed t table value for alpha error <br />probability of .20, with (n -1) degrees of freedom (infinite degrees of freedom may be used if n >30), <br />then Ho is rejected, and revegetation is deemed successful. <br />For the above (one - sample) t -test, it will be necessary to have achieved sample adequacy in the <br />reference area sampling. Were adequacy NOT to have been achieved in the reference areas, then the <br />ESCO Associates 13 -13 -7 TR40 * 03106 <br />