Summarizing by state
Another interesting column is land_area, which shows the land area in square miles. Here, you'll summarize both population and land area by state, with the purpose of finding the density (in people per square miles).
counties_selected <- counties %>%
select(state, county, population, land_area)
Ця вправа є частиною курсу
Data Manipulation with dplyr
Інтерактивна практична вправа
Спробуйте виконати цю вправу, доповнивши цей зразок коду.
counties_selected %>%
# Group by state
___
# Find the total area and population
___