Each of the columns in the data frame contains one of the variables, with the name that we gave it when we created the data frame. For example, if we wanted to access the mileage variable, we would co...Each of the columns in the data frame contains one of the variables, with the name that we gave it when we created the data frame. For example, if we wanted to access the mileage variable, we would combine the name of the data frame with the name of the variable as follows: In some of the examples in the book, you will see something called a tibble; this is basically a souped-up version of a data frame, and can be treated mostly in the same way.
