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COVER — PERFORMANCE STANDARD WITH UPWARDLY ADJUSTED MOUNTAIN BRUSH REFERENCE <br />COMPONENT <br />Sample adequacy for total vegetation cover was achieved for the reference areas and BRB -5. For total <br />allowable herbaceous cover, adequacy based on first -hit values was achieved for BRB -5 and the <br />Sagebrush Reference Area, but it was not for the Mountain Brush Reference Area. <br />In consideration of the lack of a sample size sufficient to detect a 10 percent reduction in the mean with 90 <br />percent confidence (i.e. sample adequacy), the upper limit of the possible values of the true mean (with a <br />sample size of 21) was determined. This can be done in either of two ways. <br />1) Confidence Intervals <br />S 9.15 <br />C.1. = — * t = * 1.725 = 3.44 <br />21 <br />20.95 + 3.44 = 24.39 <br />2) Sample Adequacy Expression <br />s2t2 <br />N = d2x2 <br />F=N F2— * 1722 <br />d= _ 52 * 21 <br />= 0.1644 <br />T + d = 20.95 + (20.95 * 0.1644) = 24.39 <br />24.39 percent allowable herbaceous cover represents the highest possible value of the true mean for the <br />Mountain Brush Reference Area. <br />[Note in the above two- tailed t values with n -1 degrees of freedom are used. We are concerning ourselves <br />with the full range of possible values for mean, thus bi- directional concerns are evident. From the CDRMS <br />point of view this pushes the limits out further and produces the highest maximum value for the mean (at <br />90% confidence).] <br />17 <br />