Answer:
10.5
Step-by-step explanation:
3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5
11
assumind we start from 3, the pattern goes that you add .5 each time
so, 3+0.5x
x=16
3+8=11