  <b>impute</b> missing values when a=3 and c=1 by inserting b= mean of
      non-missing b values when c=1.
    </figcaption>
  </figure>
  <div style="clear: left;"></div>

  <figure class="cell">
    <div id="transform5"></div>
    <figcaption><b>density</b> transform of IMDB ratings.</figcaption>
  </figure>
  <div style="clear: left;"></div>

  <figure class="cell">
    <div id="transform6"></div>
    <figcaption>
      <b>loess</b> transform to show trend overlaid on IMDB scatterplot
    </figcaption>