title: Excel - How do I create a cumulative sum column within a group?
body: <p>In Excel, I have an hours log that looks like this:</p>
  
  <pre><code>PersonID   Hours   JobCode
  1          7       1
  1          6       2
  1          8       3
  1          10      1
  2          5       3
  2          3       5
  2          12      2
  2          4       1
  </code></pre>
  
  <p>What I would like to do is create a column with a running total, but only within each PersonID so I want to create this:</p>
  
  <pre><code>PersonID   Hours   JobCode    Total
  1          7       1          7 
  1          6       2          13
  1          8       3          21
  1          10      1          31
  2          5       3          5
  2          3       5          8
  2          12      2          20
  2          4       1          24
  </code></pre>
  
  <p>Any ideas on how to do that?</p>