Final answer:
The constant of proportionality, represented by the symbol k, relates two variables in a proportional relationship. In a direct proportion, the relationship is expressed as y = kx. In an inverse proportion, the relationship is expressed as y = k/x.
Step-by-step explanation:
The constant of proportionality is a value that relates two variables in a proportional relationship. It can be represented by the symbol k. In a direct proportion, where a change in one variable leads to the same change in the other, the relationship is expressed as y = kx. In an inverse proportion, where a change in one variable leads to the opposite change in the other, the relationship is expressed as y = k/x.
For example, if we have a direct proportion where y doubles every time x doubles, the constant of proportionality would be 2. If we have an inverse proportion where y is halved every time x doubles, the constant of proportionality would be 0.5.