[list of commands]
Returns the numerical average of the given list.
Note: If [list of commands] contains no numbers, an error occurs. If some of the [list of commands], when evaluated, are not numbers, those values are ignored.
Examples:
average-of-list [1 2 3 4 5] returns 3, the average of the list.
Related commands: average-of-patches average-of-turtles