Question: Calculate the average game sales for the PS2 platform.
SQL: SELECT SUM(T3.num_sales * 100000) / COUNT(T1.id) FROM platform AS T1 INNER JOIN game_platform AS T2 ON T1.id = T2.platform_id INNER JOIN region_sales AS T3 ON T2.id = T3.game_platform_id WHERE T1.platform_name = 'PS2'