R Programming Language Certification Data Manipulation & Tidyverse in R

Question 1

Which tidyverse package is the primary tool for data manipulation in R?

Accepted Answer

dplyr

Answer

tidyr

Answer

purrr

Answer

stringr

Question 2

Which dplyr function selects a subset of rows based on a logical condition?

Accepted Answer

filter()

Answer

select()

Answer

slice()

Answer

subset()

Question 3

Which dplyr function adds new columns or transforms existing columns in a data frame?

Accepted Answer

mutate()

Answer

transmute()

Answer

add_column()

Answer

transform()

Question 4

What does the pipe operator |> (or %>%) do in R?

Accepted Answer

Passes the left-hand result as the first argument to the right-hand function

Answer

Creates a logical OR condition

Answer

Concatenates strings

Answer

Combines two data frames

Question 5

Which dplyr function calculates summary statistics for groups defined by one or more variables?

Accepted Answer

summarise() after group_by()

Answer

aggregate()

Answer

tapply()

Answer

collapse()

Question 6

Which dplyr function reorders rows by one or more columns?

Accepted Answer

arrange()

Answer

order()

Answer

sort()

Answer

rank()