title: excel, getting the average of the rows
body: <p>I have a <code>2000X10</code> matrix, I want to get a the average of the columns of each row and on the 11th column put all the averages, thus have a <code>1X2000</code> matrix with the averages</p>
  
  <p>How can I do that most efficiently? without just doing this</p>
  
  <p><code>=AVERAGE(A1,B1,C1,D1,E1,F1,G1,H1,I1,J1)</code></p>