{dplyr}
join two data sets keeping the observations that they have in common
{tidyr}
drop rows containing missing values
{base}
sum elements of vector
{stats}
compute standard deviation
{dplyr}
keep rows based on values of columns
{dplyr}
group data by levels of column
{base}
create vector of numbers, characters, etc.
{tidyr}
pivot data frame to be longer
{dplyr}
create or modify data columns
{base}
calculate mean of elements of vector
{dplyr}
keep specified columns
{tidyr}
pivot data frame to be wider
The end!