​Correct relation for the numbers 10, 7, 8, 5, 6, 8, 5, 8, 6 is:​

Given:
Numbers: 10, 7, 8, 5, 6, 8, 5, 8, 6

Arrange in ascending order: 5, 5, 6, 6, 7, 8, 8, 8, 10
Since there are 9 numbers (odd),
Median = middle value = 5th term = 7

Mode:
Most frequent number = 8 (appears 3 times)

​$$\text{Mean} \;=\; \frac{\text{Sum of all observations}}{\text{Number of observations}} \\[6pt]\text{Sum} \;=\; 10 + 7 + 8 + 5 + 6 + 8 + 5 + 8 + 6 \;=\; 63 \\[6pt]\text{Number of observations} \;=\; 9 \\[6pt]\text{Mean} \;=\; \frac{63}{9} \;=\; 7$$​​

Mean = 7

Median = 7

Mode = 8

Thus: mean = median