Decide whether or not each equation represents a proportional relationship. Volume measured in cups (c) vs. the same volume measured in ounces (z): c=18z Area of a square (A) vs. the side length of the square (s): A=s2 Perimeter of an equilateral triangle (P) vs. the side length of the triangle (s): 3s=P Length (L) vs. width (w) for a rectangle whose area is 60 square units: L=60w