X = randn(1, 1000000);
p = zeros(1, 9);
x = zeros(1, 9);
i = 1;
for T = -10: 0.1: 10
    x(i) = T;
    Y = find(X <= T);
    p(i) = length(Y)/length(X);
    i = i + 1;
end
plot(x, p)
grid
xlabel('x');
title('Prob[X<=x]')


    