The correct response is:
The constant of proportionality is 7. It takes the crew of workers 7 weeks to complete 1 road project.
In the given equation \( y = 7x \), the variable \( x \) represents the number of road projects, and \( y \) represents the number of weeks it takes to complete all the projects. The constant of proportionality, which is 7 in this case, indicates that for every road project, it takes 7 weeks to complete it. Therefore, if there is 1 road project, it takes 7 weeks; if there are 2 projects, it takes 14 weeks; and so on.