different stats with different rules
Inferential and descriptive:
different goals and different tools.
What's the average height of students in this room, whom I can measure?
Here you are describing data that you've got.
What's the average height of students living in Australia?
Now you are inferring something you know not.
When reporting variation in descriptive information,
interquartile range may be employed.
When reporting variation in inferential information,
standard error of the mean may fill the void.