title: not being able to do numpy operations on values on a dictionary
body: <p><code>total_minutes_by_account</code> is a dictionary with values by account.</p>
  
  <p><code>total_min</code> shows the values seperated by comma  but get the error below.</p>
  
  <pre><code>total_min=total_minutes_by_account.values()
  import numpy as np
  np.mean(total_min)
  
  File "&lt;ipython-input-17-7834a3d1e5e6&gt;", line 1, in &lt;module&gt;
      np.mean(total_min)
  
    File "/Users/newtopython/anaconda/lib/python3.5/site-packages/numpy/core/fromnumeric.py", line 2942, in mean
      out=out, **kwargs)
  
    File "/Users/newtopython/anaconda/lib/python3.5/site-packages/numpy/core/_methods.py", line 72, in _mean
      ret = ret / rcount
  
  TypeError: unsupported operand type(s) for /: 'dict_values' and 'int'
  </code></pre>