Subgroup size (min. 2):
Pooled standard deviation:
\n", $mean); if($pool=="1") { $dif = array(); $sum = 0; for($i=1; $i<=count($means); $i++) { $dif[$i] = $means[$i] - $mean; $dif[$i] = $dif[$i] * $dif[$i]; $stdev = sqrt($dif[$i]); $dif[$i] = $stdev; $sum = $sum + $stdev; } $stdev = $sum / count($means); } else { $dif = array(); $sum = 0; for($i=1; $i<=count($means); $i++) { $dif[$i] = $means[$i] - $mean; $dif[$i] = $dif[$i] * $dif[$i]; $sum = $sum + $dif[$i]; } $stdev = $sum / (count($means)-1); $stdev = sqrt($stdev); } printf("Standard deviation: %f
\n", $stdev); printf("Go to the Phase II
", $mean, $stdev, $subsize); } include("footer.inc"); ?>