There's a similarity between prudence and political knowledge. Prudence can be involved in legislative work, or more specifically, with the "political art."
In a more general sense, a prudent person applies his skills to himself. Aristotle also discusses other types of prudence here.
A person who knows himself well and tends to his own business is considered prudent.
It's possible to have scientific knowledge but not prudence, from lack of experience—kind of like an 8th grader who knows more algebra than his parents but can't figure out that taking regular showers makes him more socially acceptable.
Aristotle emphasizes that prudence is not knowledge. Remember always that it is concerned with one narrow thing: what is best to do (i.e. action).