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SAMPLE ADEQUACY CALCULATIONS <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 />Nmin t 5 <br />~xmean <br />where: <br />~ =one-tailed t-value with (n-1) degrees of freedom, a=0.10 <br />s =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 2/03) <br />xmaan =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 />• CONFIDENCE LIMITS <br />Confidence limits for comparisons to reference-area-based performance 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. = to ~ <br /> Jn <br />where: <br />to =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 />LJ <br />