Question

when the data points on the graph show a straight line we can assume the relationship between the variables is _ because _. mass vs. volume of water slope = \\(\frac{rise}{run}=\frac{5 g}{5 cm^{3}} = 1 g/cm^{3}\\) direct // the product of the two variables is a constant direct // the ratio of the two variables is constant inverse // the ratio of the two variables is constant inverse // the product of the two variables is a constant

Explanation:

In a direct - relationship, the ratio of the two variables is constant. When the graph of two variables is a straight line passing through the origin (in the case of a proportional direct - relationship, which is a special type of direct relationship), the slope (ratio of the change in the y - variable to the change in the x - variable) is constant. Here, for mass and volume of water, the slope of the line is $\frac{\text{Rise}}{\text{Run}}=\frac{5g}{5cm^{3}} = 1g/cm^{3}$, indicating a constant ratio between mass and volume. In an inverse relationship, the product of the two variables is constant.

Answer:

direct // the ratio of the two variables is constant