... u - px > s2) + 0.5*sum(u > px & u - px == s2) rx = qx * px pfx = qx * (px-m) par(cex=0.7,mar=c(3,3,3,2)) st = ifelse(id == 1, ... 4.5 產品差異的重要性.
確定! 回上一頁