In this problem
x represent the cups of water
y represent cups of lemon juice
Part 2
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
y=kx
where k is the constant of proportionality
so
Find the value of k in the table
k=y/x
For x=2, y=3 ------> k=3/2=1.5
For x=4 y=6 ------> k=6/4=1.5
For x=5 y=7 ------> k=7/5=1.4
therefore
is not proportional
