normcdf = @(x,sigma) 1/2*erfc(-x/sigma/sqrt(2));

mean_1  = 70.4;
sigma_1 = mean_1*0.03;

mean_2  = 67.4;
sigma_2 = mean_2*0.007;

% difference distribution is gaussian 
sigma_diff = sqrt(sigma_1^2+sigma_2^2);

delta = abs(mean_1-mean_2);
significance = 2*(1-normcdf(delta,sigma_diff));
fprintf('Mahalanobis distance: %.2f\n', delta/sigma_diff)
fprintf('Difference significance: %.1f%%\n',significance*100)