Hi! What pronoun would you choose to replace "the average person"?
eg. How much trash does the average person throw away every day? 
The average person produces about 2 kg of trash per day.
Thanks.
Sorcha
Hello Sorcha, 
 
In my opinion, in Sentence 1, you cannot substitute a pronoun, �he�, �she�, �they�, �one�, �someone�, �anybody�, without changing the sense of the sentence.  You are asking about �the average person�, not some unknown person.  You are thinking about a specific type of person.
 
In the UK, in Sentence 2, because you are asking for information about �the average person�, this would become �he/she� ; �s/he�;  �he or she� (in a formal situation), but many people would use �he�, or �they�, (in an informal situation):
 
"He produces ... "; "They produce ... ... "
 
I think that the majority of people in a formal University situation here would write, and say:
 
("He/she" ... ... .)  "He or she produces about 2 kgs. of rubbish per day".
 
This is my opinion.  I hope that it helps.
 
Les