Answer
The regular Coke is more dense.
Work Step by Step
In order to create a box and whisker plot, we use a box and a whisker plot maker online.
(To draw one by hand, we draw a line, making the far left point the minimum and the far right point the maximum. Then, we draw a box, where the left side of the box is $Q_1$ and the right side of the box is $Q_3$. Finally we draw a vertical line through the box: this is will be the median.)
After doing this, we find that the box for the regular Coke is further right than the box for the Diet Coke, meaning that the regular Coke is more dense.
