11. (5 points) A team of 23 people participated in the 16th Guangzhou Asian Games. They were arranged in descending order of height. The average height of the top 5 players is 3 cm more than the average height of the top 8 players; the average height of the last 15 players is 0.5 cm less than the average height of the last 18 players. How much more is the average height of the top 8 players compared to the average height of the last 15 players?
【Answer】Solution: The average height of positions $6 \sim 8$ is less than the first 5 positions by: $3 \div 3 \times 8=8$ (cm); therefore, the average height of positions $6 \sim 8$ is more than the average height of positions $9 \sim 23$ by $0.5 \div 3 \times 18=3$ cm. The average height of the first 8 positions is more than the average height of positions $9 \sim 23$ by $8-3+3=8$ cm.