Answer:
Linear
Explanation:
The hypothese is the function is linear. Lets prove it .
If we divide the difference of 2 any function's values by the difference of the corresponding argument's values we will get the same ratio 0.48(for instance 19.210-18.250=0.96 delete be 2-0=2 will get 0.48) .
Lets calculate any other pair of y (function) and x ( argument) :
(20.170-18.730)/(4-1)=1.44/3=48 as we can see we'll get the same ratio 0.48.
That means that function is linear