clear
x0 = 100;
s_a = 10;
s_s = 5;
N = 4;
nREP = 1000;
%xm = zeros( nREP, 1 );
for qR = nREP : -1 : 1
    x = gera_dados( N, x0, s_a, s_s );
    xm(qR,1) = mean( x );
% sx = std( x )
end
sf_exp = std( xm )