On a coordinate plane, a line goes through points (1, 4) and (2, 8). Use the graph to find the relationship between the two variables. Select all that apply. The two variables are books and months. The two variables are 4 and 8. Books is the independent variable, and months is the dependent variable. Months is the independent variable, and books is the dependent variable. The relationship is y = 4x. The relationship is x = 4y.