Answer:
3/2
Step-by-step explanation:
Image a bit blurry, but I'm counting whoever wrote this was sane enough to pick integer values.
[tex]f(2) = 1; f(4)=4[/tex]
Average rate of change is the difference in f divided by the difference in x:
[tex]\frac{\Delta f(x)}{\Delta x} = \frac{4-1}{4-2} = \frac32[/tex]
