Passage: The opening weekend, February 1–3, 2008, the movie had gross revenue of $31.1 million. It was the number one movie of the weekend. Opening in only 638 theaters, it set a record of over $42,000 per theater. It set a record for the highest revenue for a 3-D movie for one weekend.

Question: What was the average box office per theater the movie earned?
$42,000