What does a constant of proportionality indicate in a direct variation?

In a direct variation, the constant of proportionality is the factor that relates two variables that change together in a consistent ratio. When one variable increases or decreases, the other variable does so in a proportionate manner, which reflects their linear relationship. The constant of proportionality essentially acts as the scale factor, determining how much one variable affects the other.

For example, if you have a direct variation between variables ( y ) and ( x ), and it can be expressed in the form ( y = kx ) (where ( k ) is the constant of proportionality), then for every unit increase in ( x ), ( y ) will increase by ( k ). This consistent ratio between the two variables clearly illustrates their proportional relationship. Thus, identifying the constant of proportionality provides valuable insight into how strongly and in what manner the variables are linked, making option B the best choice.