Laserfiche WebLink
t2s2 <br />�fi = (a)2 <br />where: <br />nm = minimum sample size <br />S = Sample variance (n -1 degrees of freedom) <br />d = Precision (0.10 for cover and production; 0.15 for woody <br />plant density) <br />X = Sample arithmetic mean <br />t = The (a =.10) t -table value for a 1 tail t -test, n -1 degrees of <br />freedom (infinite degrees of freedom may be used if n> 30) <br />n = Sample size <br />(b) If the reclaimed area sample mean is less than 90 percent of the relevant standard, a one <br />sided Nest with alpha error probability of 0.10 shall be used to demonstrate that the reclaimed <br />area mean is not less than 90 percent of the applicable success standard with 90 percent <br />statistical confidence. If the basic assumption, or null hypothesis, of equality between the <br />reclaimed area and 90 percent of the standard is not rejected by the test, then reclamation is <br />considered successful for the parameter tested. This is the "standard null' hypothesis approach <br />to the t -test. Sample size adequacy must be demonstrated using the formula in (a) above. A <br />minimum of 15 sample observations shall be taken even if statistical sample adequacy is <br />achieved with fewer observations. <br />The general form of the "standard null' Nest is: <br />August 2013 PR -08 2.05.4(2)(e) - 47 <br />