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tt = Table t value (alpha = 0.2) <br />The (reverse) null hypothesis being tested would be that the bond release block mean (µ) was less than <br />or equal to 90% of the standard, stated as Ho: p _< Q. If tc was greater than the 1- tailed t table value for <br />alpha error probability of .20, with (n -1) degrees of freedom then Ho would be rejected, and revegetation <br />would be deemed successful. <br />Under the previous scenario if sample adequacy was not met for the reference areas nor the BRB -5 <br />(minimum of 30 samples), then the hypothesis of reclamation success would be tested using a Two - <br />sample t-test of Reverse Null Hypothesis with Satterthwaite's Adjustment (CDMG 2010 proposed rules <br />revisions, 4.15.11 (2)(c)). <br />The reverse null hypothesis states the mean of a given vegetation parameter in the revegetation area <br />(pbr) is equal to or less than 90% of the mean on the reference area (pref). <br />H,, : pbr — 0.9 * ,uref < 0 <br />Ha • lubr — 0.9 * ,uref i 0 <br />Evidence in support of revegetation success is obtained when the null hypothesis is rejected. <br />Assumptions for this test include approximate normality and independence of observations between the <br />two groups. <br />The test statistic is: <br />xbr — 0.9— X re f <br />t` _ <br />sYef )z <br />—+ <br />nbr nref <br />and the degrees of freedom are: <br />SE4 <br />sat <br />df,, _ <br />( SEbr + (0.9 *SEref)4) <br />nbr —1 nYef —1 <br />Where: Kr is the revegetation sample mean, <br />xref = the reference area sample mean, <br />s2br = the revegetation area variance, <br />s2ref= the reference area variance, <br />SEbr= the revegetation area standard error of the mean, <br />7 <br />