It really depends on the exact structure of data you want to end up with.
Simply taking one array ($row) and putting it into another identical array called $people is kind of pointless. So I presume there is some further processing of the data going on.
mysql_fetch_assoc(), along with all its sister functions has been removed from PHP a year ago. Not to mention there are other ways to get what you want right from the query, without any loops at all. Namely PDO.
$stmt = $pdo->query("SELECT number, fname FROM whatever")
$people = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);