Problem set $4$:

$($LC$4\mathrm{.}1)$ What are common characteristics of $$tidy$$ data frames?

$($LC$4\mathrm{.}2)$ What makes $$tidy$$ data frames useful for organizing data?

$($LC$4\mathrm{.}3)$Take a look the airline$\_$safety data frame included in the fivethirtyeight data package. Run the following:

airline$\_$safety