title: rpart regression tree interpretation
body: <p>I applied rpart.plot on my regression tree, but I do not know what the values inside the nodes refer to. and how the root is selected?
  many thanks.could you please explain what are the values inside of each node? (The picture shows my problem )</p>
  
  <p><a href="https://i.stack.imgur.com/tEofb.png" rel="nofollow noreferrer">https://i.stack.imgur.com/tEofb.png</a></p>