7. In a certain archery competition, the full score is 10 points, and in the preliminary stage, 50% of all participants are eliminated. It is known that the average score of the contestants who advance to the finals is 2 points higher than the average score of all contestants, and the average score of the contestants who advance to the finals is 8 points. Then the average score of the eliminated contestants is
【Analysis】Suppose there are $2 n$ people in total, then the number of participants who enter the semi-final is $n$ people, and the number of participants who are eliminated is also $n$ people. The average score of all participants is 6 points, so the total score is $6 \times 2 n=12 n$ points. The total score of the participants who enter the semi-final is $8 \times n=8 n$ points, so the total score of the eliminated participants is $12 n-8 n=4 n$ points, and the average score is $4 n \div n=4$ points.