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<br />.. = the c.ean of the >: values usrd to deterr.ine tLc r~del <br />i <br />n <br />x 1 <br />1=1 <br />Therefore, for }•ear one of testing for vegetation success, the lower bound of <br />estir„ation with 90% confidence is described by: <br />50.8 - (1.856)(3.77) <br />50.8 - 8.5 = 42.3 <br />218.75 <br />A similar calculation can be carried out for }•ear 2. If the values from the <br />revegetated area equal or exceed the lower prediction limits, they fall within <br />the bounds of estimating error of the model and indicate successful revegeta- <br />tion. After two consecutive }•ears of testing for revegetation success, the aver- <br />age values from the revegetated area will be compared to the average of the lower <br />prediction limits, e.pz. <br />Lower prediction limit; year 1 42.3 <br />" year 2 36.4 <br />Value from revegetated area; year 1 50.0 <br />" year 2 55.0 <br />Average 2 }•ear lower prediction limit = (42.3 + 36.4) 2 = 39.4 <br />Average 2 }•ear value from revegetated area = (50.0 + 55.0) 2 = 52.5 <br />52.5 > 39.4 so revegetation would be deemed successful. <br />'this approach to evaluating success of revegetated areas is statistically more <br />ce~plex than simple hypothesis testing. However, it takes into consideration <br />the }•ear-to-}•ear variation in the relationship between the reference area and <br />the pre~~ine area and the accuracy of the estimate of such a relationship. <br />Simple hypothesis testing requires the tenuous assumption that a 1:] relation- <br />ship e>:isted between the reference area and the premine area and that it alwa}•s <br />4-]09 <br />