Answer:
A proportional relationship is one in which two quantities vary directly with each other.We say the variable varies directly .If y=k.x then as x increases y also increases.Here k is called the constant of proportionality.
The given equation y = 4.2x is of the form y=k.x where k= 4.2 as x increases y value will also increase. The relation is called a proportional relationship.
Explanation: