The number of possible batting lineups is 720
<u><em>Explanation</em></u>
Total number of players in the team = 9
The center fielder must bat fourth, the second baseman must bat third and the pitcher last. That means, <u>3 slots in the batting line-up are already assigned to 3 players</u>.
So, the remaining (9 - 3) = 6 players will be assigned to remaining 6 slots.
Thus, the possible number of ways so that 6 players can be assigned to 6 slots will be: