フリードマン検定
xij = [ [13.6, 15.6, 9.2], [22.3, 23.3, 13.3], [26.7, 28.8, 15.0], [28.0, 31.2, 15.8], ] twoWay = Num4AnovaLib::TwoWayLayoutLib.new twoWay.friedman_test(xij, 0.05) => true