Exercise

# Functions continued

In the last exercise we made a start with functions. Also, we looked at how we could get help on using functions.

When getting help on the mean function, you saw that it takes an argument x. X here is just an arbitrary name for the object that you want to find the mean of. Usually this object will be an R vector. We also saw the `...`

. This is called an elipsis and is used to provide a number of optional arguments to the function.

Remember that R can match arguments both by position and by name. Let's say we want to find the mean of a vector called temperature. An example of matching by name is the following:

`mean(x = temperature)`

An example of matching by position is the following:

`mean(temperature)`

In this exercise, we have provided you with a vector of 5 numbers. There are the grades that you got during the semester.

Instructions

**100 XP**

- Calculate the mean of the vector
`grades`

using matching by position - Calculate the mean of the vector
`grades`

using matching by name