title: How to plot a probability mass function in matlab
body: <p>I am new to matlab and would like to know how to plot a graph when it states</p>
  
  <pre><code>a =  -1    0   1       2       3
  ----------------------------------
  p(a)1/24  1/2  1/4   1/6     1/24
  </code></pre>
  
  <p>Any tips on how to do it would be helpful!</p>