title: Midpoint between range in R
body: <p>I have a column that has estimated numbers for a conversion rate that looks like;</p>
  
  <pre><code>Type  Conversion
  A      90
  B      84
  C      85-90
  D      60-70
  </code></pre>
  
  <p>The problem is, I need to create a new column that takes the midpoint if the conversion was given in a range. So something like this;</p>
  
  <pre><code>Type   Conversion
  A      90
  B      84
  C      87.5
  D      65
  </code></pre>
  
  <p>How can I do this in R? </p>