x normalized by A 怎么用数学表达式表达
 

用matlab做曲线拟合，得出结果
f(x) = (p1*x^4 + p2*x^3 + p3*x^2 + p4*x + p5) /(x^4 + q1*x^3 + q2*x^2 + q3*x + q4)
where x is normalized by mean 16.42 and std 17.79

这里的 x is normalized by mean 16.42 and std 17.79 如何用表达式表达阿。。