For a proportional representation system with a 200 seat leg…

For a proportional representation system with a 200 seat legislature, a) How many seats would each party win if Party A got 23% of the vote, Party B got 37% of the vote, Party C got 15% of the vote, party D got 25% of the vote? b) explain why small parties are better off in a proportional representation system as opposed to how we do it in the US.  (Please label your answer for the two parts of the question.)