The number of seven cooperative learning groups in a class is as follows: 5, 5, 6, x, 7, 7, 8. Given that the average of this group of data is 6, the median of this group of data is () A. 7B. 6C. 5.5D. 5

The number of seven cooperative learning groups in a class is as follows: 5, 5, 6, x, 7, 7, 8. Given that the average of this group of data is 6, the median of this group of data is () A. 7B. 6C. 5.5D. 5

According to the meaning of the question, (5 + 5 + 6 + X + 7 + 7 + 8) = 7 × 6, the solution is x = 4, in 4,5,5,6,7,7,8, the median is 6