[A] Section 2.3, 2.4
Also read Chapter 5 (Data transformation) of the free online book R for Data Science.
This lecture as: slideshow (html), Rmarkdown (Rmd), notes (pdf).
The entire module: notes (pdf).
First, run the commands in the two case studies on Moodle and add some plots or summaries of your own.
Second, solve the following exercises with the flights
dataset in Chapter 5 of R for Data Science: