If X is 1 and Y is 1/2

IF x is 2 and Y is 1
IF x is 3 and Y is 1 1/2
IF X is 4 and Y is 2

What is the constant?

Based on the given information, it can be observed that as x increases by 1, y also increases by 1/2. This relationship between x and y implies that the constant is 1/2.