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SAMPLE ADEQUACY CALCULATIONS <br />• <br />Sample adequacy calculations for parameter estimation without hypothesis testing were carried <br />out using the formula as prescribed by the Colorado Mined Land Reclamation Board (CMLRB <br />1995): <br />zz <br />min= <br />~Xmean <br />where: <br />to =one-tailed t-value with (n-1) degrees bf freedom, a=0.10 <br />sz =sample variance <br />d =level of precision or desired detectable reduction (0.1 for cover and production, 0.15 for <br />woody plant density as per proposed DMG rule changes pending as of 2103) <br />x,,,aan =sample mean <br />In order to bring the negatively skewed distribution of woody plant data into closer conformance <br />with normality, a square root transformation was undertaken before sample adequacy calculation. <br />• <br />CONFIDENCE LIMITS <br />Confidence limits for comparisons to reference area based pertormance standards and technical <br />standards were calculated using a 1-tailed t-value for alpha error probability of 0.10 (0.15 for <br />woody plant density) at (n-1) degrees of freedom multiplied by the standard error of the mean of <br />the sampled area: <br />C.I. _ >n ~ <br /> Jn <br />where: <br />fa =one-tailed t-value with (n-1) degrees of freedom, a=0.10 <br />s =sample standard deviation (n-1) <br />n =number of samples <br />• <br />