Exercise

# The by function

The box plots show how the medians of the two distributions compare, but we can also compare the means of the distributions using the `by()`

function to split the *weight* variable into the *habit* groups, and then take the mean of each using the `mean()`

function.

You can use the `by()`

function as follows to compare the means of the groups:
`by(numerical_dataset, categorical_dataset, mean)`

.

You can also use other functions like `median`

, `summary`

, etc.

Instructions

**100 XP**

Use the `by()`

function to find out how the means of the distributions compare.