Using the str function, we saw that the region column stores a factor. You can corroborate this by using the class function on the region column.

class(murders$region)
#> [1] "factor"

The question of this exercise is how many regions are included. For this question we will combine two functions, in a nested way, to determine the number of unique categories. Use the functions levels and length to determine the number of regions defined by this dataset and contained in murders$region.

NOTE

Do not forget to first load the data as in the previous exercises!