-1 Data structure: It looks like you may have overlooked or misunderstood how to format your data. It should have the structure listed in this cell (`chart_data`) such that the keys are *generic*. That way, your visualization code will read something like: .attr("x", d => xScale(d.x)) We encourage this so that you can easily reuse your charting code.

I added the animation for the bar chart and xScale and yScale

-1 No animated transition: See this notebook: https://observablehq.com/@d3/selection-join. The last example shows how you can set some initial visual attributes (on the enter) and then change them for the update.

Nice work figuring out how to get the legend in there!

-1: you clearly know how to do each of these steps, as is evident in your charts, but you'll need to create them separately here, as was asked in the notebook.

Please read the questions for scales and marks again and implement them one by one.

Great work overall! See comments below on how to get those last few points!