Given the table between x and y
For each row, we will find the ratio between x and y as y/x
So,
When x = 10 and y = 18 , y/x = 18/10 = 1.8
When x = 11 and y = 18.6 , y/x = 1.69
When x = 12 and y = 19.2 , y/x = 19.2/12 = 1.6
so, the ratio y/x is not constant for all the rows
so, previous representation is not proportional