The mean is the average of the numbers.

The Median is the "middle" of a sorted list of numbers.

The mode is the number that is repeated more often than any other.

$$6,7,7,6,8,7,8,10,9$$

Rearrange the 9 scores in order.

$$\rightarrow 6,6,7,7,7,8,8,9,10$$ $$Mean=(6+6+7+7+7+8+8+9+10)\div9=68\div9\approx7.55$$ $$Median=7$$ $$Mode=7$$

After correcting the 9th score to 10.

$$\rightarrow 6,6,7,7,7,8,8,10,10$$ $$Mean=(68+1)\div9\approx7.66$$ $$Median=7$$ $$Mode=7$$

Only the mean is changed.