Constant of proportionality is the constant value of the two proportional quantities, in this problem p and s, where 4 is the factor of proportionality because it is constant or k.
In simple terms, p is in direct proportion to s wherein the increase or decrease in value of s results to the increase or decrease in value of p with 4 the only factor remaining unchanged.
In the above problem, the number 4 is derived from the word square. We all know that a square has 4 sides of equal lengths, therefore, the perimeter is equivalent to the product of 4 and its lenght.
