Exercises

1. What function is used to filter data?
2. What happens when group_by() is used without the summarizing function?
3. Write the code to return the capital_gain mean grouped by native_country.
4. What’s function is used to drop all NAs from a dataset?
5. Write the code to replace NAs with another value.
6. Write the code to return the average net gain (capital_gain – capital_loss) by education level, arranged in decreasing order.
7. What is the main function to be used to create new variables?
8. List all the types of joins.
9. What is the difference between left join and inner join?
10. What are the two functions used to reshape data?