Answer and Step-by-step explanation:
Since we have given that
Time Average age of a marriage
0 10
10 11.2
20 13.9
30 17.2
40 29
We need to show that the above data indicated a non linear model.
For this it is enough to show that slope is different:
So, we consider the slope for first 2 points:
(0,10) and (10,11.2)
So, slope becomes
and similarly, (10,11.2) and (20,13.9)

so,

So, it becomes non linear model.