Laserfiche WebLink
• Statistical Methods <br />Sample adequacy calculations were carried out using the formula as prescribed by CMLRB <br />(1 988): <br />t2 sz <br />Nmin = <br />d2 x2 <br />where: <br />t = two-tailed t-value with n-1 degrees of freedom <br />s2 = sample variance (based sn-1) <br />d = 0.1 (level of precision or desired detectable reduction) <br />x =sample mean <br />For the two-stage sampling of shrub density, calculation of sample variance for use in the above <br />sample adequacy formula was as follows (expression 10.10 of Cochran 1963): <br />1 -f 1 1-fp <br />Vy = S12 + S22 <br />• n mn <br />where: <br />Vy = Overall variance of shrub density data <br />f1 = n/N <br />f2 = m/M <br />S12 = variance among primary unit means <br />SZ2 = variance among elements within primary units relative to the ~marv unit means <br />N =total number of primary units that exist (and are to be potentially sampled) <br />n =number of primary units actually sampled <br />• 7 <br />