title: Summing Variable in R
body: <p>I would like to computer the sum of variable A in R.</p>
  
  <p>This is my dataset and I would like to sum VariableA and Variable B so that I can convert them into a metrics that involves Sum of Variable A/Sum of Variable B in percentages.</p>
  
  <p><img src="https://i.stack.imgur.com/cVNqk.png" alt="enter image description here"></p>
  
  <p>This is the code that I wrote:</p>
  
  <p><img src="https://i.stack.imgur.com/TUzhk.png" alt="enter image description here"></p>
  
  <p>Is this right?</p>
  
  <p>If you need any clarification, please let me know!This is my first time working in R so any advice is welcomed. </p>