title: How to subset data in R?
body: <p><a href="https://i.stack.imgur.com/mbhEQ.jpg" rel="nofollow noreferrer"></a>
  We have this question in our R lab. I wrote heartFailure=hospital[&quot;MORT_30_HF&quot;,&quot;Measure.ID&quot;] for part b, I am not sure if it's right though. Then, I tried part c) over and over and still didn't understand how to approach anyways.
  <a href="https://i.stack.imgur.com/mbhEQ.jpg" rel="nofollow noreferrer">enter image description here</a></p>