I'm writing a formal research paper (Highschool)
I have lots of statistics involving money (In fact, my whole essay is about the economy).
So a question arises about the format of writing money.
Would it be:
The company spent $4.5 billion dollars.
or simply
The company spent $4.5 billion.
Do I need to include the "dollars" at the end? Which one is more customary?
Thank you