The mean of these 8 numbers is 9 and their range is 8. What are the 2 missing numbers

6,11,9,7,8,13,?,?

With range = 8 one of the missing numbers is 5 or 14.

Mean = ∑x/n

(5+6+11+9+7+8+13+x)/8 = 9

Solve for x. If necessary, try with 14.