title: to show mean value in ggplot box plot
body: <p>I need to be able to show the mean value in ggplot box plot. Below works for a point but I need the white dashed lines? Any body help?</p>
  
  <pre><code>x
  
  Team     Value
  A        10
  B        5
  C        29
  D        35
  ggplot(aes(x = Team , y = Value), data = x) 
  + geom_boxplot (aes(fill=Team), alpha=.25, width=0.5, position = position_dodge(width = .9)) 
  + stat_summary(fun.y=mean, colour="red", geom="point")
  </code></pre>