diff --git a/exercises/mlclass-ex1/featureNormalize.m b/exercises/mlclass-ex1/featureNormalize.m
index 08abdc7..02eecf4 100644
--- a/exercises/mlclass-ex1/featureNormalize.m
+++ b/exercises/mlclass-ex1/featureNormalize.m
@@ -27,9 +27,8 @@
 %       
 mu=mean(X);
 sigma=std(X);
-for i=1:size(X,2)
-  X_norm(:,i)=(X(:,i).-mu(i))./sigma(i);
-end
+x_size = length(X);
+X_norm = (X_norm - repmat(mu,x_size,1)) ./ repmat(sigma,x_size,1);
 % ============================================================
 
 end