Stephen Ross, the billionaire real-estate magnate, is gearing up for the Miami Grand Prix this weekend—and he has no plans to give up the Formula 1 event anytime soon. Ross recently turned down a $10 billion offer to take over his sports enterprise, which includes the grand prix, the Miami Dolphins, and Hard Rock Stadium, USA Today reported on Wednesday. The businessman rejected the offer because he wants to keep the ventures within his family, two people with knowledge of the situation who asked to remain anonymous told the newspaper. “I put the Dolphins’ entire operation, not just the team, in the Top 5 in the ... (full story)