% Verifying the Area Under a PDF 

clc;
n = 1000000;
x = randn(n,1);
v = [-1.645;1.645];
c = length(x(x >= v(1) & x <= v(2)));
area = c/n;
disp(['Area under N(0,1) PDF 2 Standard Deviations from the Mean = ' num2str(area')]);