x 3 9 13 20
y 9 27 39 60
State whether the relationship between the variables in the table is a direct variation, an inverse variation, or neither. If it is a direct or inverse variation, write a function to model it.
This relationship is a direct variation, as the ratio between the x values and the corresponding y values is always the same, which is 3.
Therefore, the function to model this direct variation relationship is y = 3x.