Final answer:
The ratio of the change in y to the change in x for a line is called the slope.
Step-by-step explanation:
The ratio of the change in y to the change in x for a line is called the slope. It is also known as the gradient, m. The slope of a line can be calculated by dividing the change in the y-value by the change in the x-value. For example, if the change in y is 4 and the change in x is 2, the slope would be 4/2 = 2.