Visualization #$3$: The horizontal axis shows the ranking $(1$ to $19)$ of the cost$-$per$-$click $($CPC$)$ for nineteen search keywords in an online ad campaign, whereas the vertical axis shows the ranking of click$-$through$-$rate $($CTR$)$ for the keywords. The size of the bubble indicates the number of clicks $($the bigger, the more clicks$).$

Hint: This is a scatter plot $($to answer the firplease try to answer the following questions $($unless otherwise noted$)$:

$(1)$ What type of chart$/$plot is it$?$ In what situation$($s$)$ would such chart$/$plot be the most appropriate$/$useful$?$

$(2)$ What can you see$/$learn from the chart$/$plot$?$ Please make sure you state an observation even when it is obvious.

$(3)$ What business decision$($s$)$ may be sensible based on the chart$/$plot$?$ Why? If you do not believe the chart$/$plot implies any actions, explain the reason$($s$).$

$(4)$ How would you have improved the visualization $($to make it more clear or more informative$)?$

Feel free to go beyond these questions as necessary.st question$),$ but it is not a typical scatter plot.