Major League Baseball (MLB) has two leagues: the American League (AL), which utilizes the designated hitter (DH) to bat for the pitcher, and the National League (NL), which does not allow the DH. A player's batting average is computed by dividing the player's total number of hits by his official number of at bats. The batting averages for all AL and NL players with at least 100 official at bats during the 2013 season are stored in the MLBAL and MLBNL files, respectively. Determine whether each batting average distribution is approximately normal.