title: Columns with frequency and avg number
body: <p>From a data frame like this</p>
  <pre><code>data.frame(id= c(1,1,2,3,3), visits = c(32,30,1,2,4))
  </code></pre>
  <p>How is it possible to produce a average number column of visits per numi but also add a new column which will have the number/frequency of numbers exist in numi column
  Expected output:</p>
  <pre><code>data.frame(id=  c(1,2,3), numi_frq = c(2,1,2), average = c(31,1,3))
  </code></pre>