Answer:
4
Step-by-step explanation:
If two variables are proportional then
...(i)
where, k is constant of proportionality.
The given equation is
...(ii)
where,
s = number of cups of seltzer.
c = cups of cranberry juice.
On comparing (i) and (ii), we get
Independent variable:
Dependent variable:
Constant of proportionality:
Therefore, the constant of proportionality is 4.