Use of the matplotlib.pyplot.plot option of a label was not previewed in any step, in this mission or any prior mission, I think, before it was used in the model solution of mission 147 step 4.
I. eventually, understood the matplotlib.pyplot.plot was supposed to be used in this step’s task, based on step 2 of mission 147, Introduction To The Data–finding how to create a label for the plots was not stated. To find that out required multiple searches, through my takeaways, through internet search engines, and finally, through the matplotlib documentation, ending up at the page https://matplotlib.org/3.2.1/api/_as_gen/matplotlib.pyplot.plot.html?highlight=plot#matplotlib.pyplot.plot.
On that page, I had to browse through four screens of documentation to find information about **kwargs, which then had a code sample showing how to label a line in a matplotlib plot.
Please consider making how to use the label option of the matplotlib.pyplot.plot method more explicit in the lessons or takeaways.