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Appendix A - Vegetation Sampling for 2003 <br />Fifteen quadrats in the NW-1 area will be surveyed prior to evaluation of sample adequacy. Sample <br />adequacy for vegetation cover within the NW-1 area will be determined using the Snedecor-Cochran <br />sample adequacy formula (Equation 2). <br />(2) <br />Q s2 <br />Nmin = - <br />(d x )2 <br />Where: <br />Nini„ = the minimum number of quadrats needed, <br />t = the a = .10 t-table value for a single-tailed t-test with n-1 degrees of freedom, <br />s2 = the sample variance, <br />d = .1 (level of precision for estimate of the mean to be within 10 percent of the <br />actual mean), and, <br />X = sample mean <br />Vegetation cover data from the quadrats will be used to determine sample size adequacy. <br />Per CDRMS guidelines on statistical evaluations (CDRMS Guidelines for Compliance with Land Use and <br />Vegetation Requirements for Coal Mining, November 28, 1998; Section V, A, Paragraph 2), "In some <br />cases, vegetation community structure is such that obtaining an adequate sample for certain parameters is <br />exceedingly difficult. An upper limit of 50 samples is usually set, if appropriate sampling procedures ... <br />are followed." <br />Golden Eagle_NWV Phase 11 proposal 7-14-08.doc A-3