Final answer:
The constant of proportionality in the equation 3y=2x is 2/3. This reflects the directly proportional relationship between y and x.
Step-by-step explanation:
The equation 3y=2x represents a directly proportional relationship between y and x. In such relationships, as one variable changes, the other changes in the same ratio. The constant of proportionality (k) is the factor by which the variables are multiplied to relate to one another.
In the given equation, if we solve for y in terms of x, we get y = (2/3)x. This is in the standard proportional format y = kx. Therefore, the constant of proportionality in the equation 3y=2x is 2/3.