use matlab we need 2 functions files:

If a random variable X is distributed normally with mean=0 and standard deviation =1, the probability that LaTeX: 0\le X\le x 0 X x is given by the standard normal function LaTeX: \Phi\left(x ight) ( x ) . This is usually looked up in a table in a statistics textbook, but can be computed as: LaTeX: \Phi\left(x ight)=0.5\:-\:r\left(at+bt^2+ct^3 ight) ( x ) = 0.5 r ( a t + b t 2 + c t 3 ) , where a = 0.4361836, b = -0.01201676, c = 0.937298, r = LaTeX: \frac{exp\left(-0.5x^2 ight)}{\sqrt{2\pi}} e x p ( 0.5 x 2 ) 2 , and t = LaTeX: \frac{1}{1+0.3326x} 1 1 + 0.3326 x . Write a function to compute LaTeX: \Phi\left(x ight) ( x ) . Use this function in a program to write out its values for LaTeX: 0\le x\le4 0 x 4 in steps of 0.1. As a check: LaTeX: \Phi\left(1 ight)=0.3413 ( 1 ) = 0.3413 .