Hint 7: Showing the field on the public user profile
This is the last time we'll look at the analysis:
It's about users.
We need to add a field to the profile.
It's a field for the shoe size.
The field should only accept values from 39 until 47.
It can be empty.
It should be editable on the admin member edit page.
It should be visible on the public user profiles.
The 7th and last bullet is about public user profiles. So find the profile templates and edit it to show the shoe size if it's available. The template should help you to do this right, but if you want you can always check the documentation :).