Mastering simple joins
Three new data.tables have been loaded into your R session containing information about the geography and population of Australia: area, capitals, and population. Your goal is to perform a sequence of joins to build a single data.table containing information about the geographical area of each Australian state and the population of its capital city, storing the final result in a new variable: australia_stats. There are three data.tables so you will need to perform two joins. First, you will join capitals and population, and then you will join the resulting data.table to the area.
This exercise is part of the course
Joining Data with data.table in R
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Identify the key for joining capitals and population
capitals_population_key <- ___
# Left join population to capitals
capital_pop <- ___
capital_pop